{"title":"Askar Field Flatteners, Reducers \u0026 Coma Correctors","description":"\u003cp\u003eAskar field flatteners and reducers are matched to specific Askar telescopes to flatten the field or shorten the focal length for imaging. The range includes 1x flatteners and 0.8x reducers for the 103APO, 120APO, 140APO, 160APO and 185APO, reducers for the PHQ, F and FRA lines, and a 0.85x reducer for the 80ED.\u003c\/p\u003e\u003cp\u003eThe Sharpstar 3\" 0.85x MPCC (CRC3085) adds a coma corrector with a slight reduction. Each corrector is designed for one optical system, so choose the model named for your tube.\u003c\/p\u003e","products":[{"product_id":"askar-2-5-f-3-9-full-frame-reducer-for-fra400-and-fra500","title":"Askar 2.5\" F\/3.9 Full Frame Reducer for FRA400 and FRA500","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces focal ratio to a fast f\/3.9\u003c\/li\u003e\n\u003cli\u003e0.7x reduction factor\u003c\/li\u003e\n\u003cli\u003e44mm image circle fully illuminates full-frame sensors\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus for easy camera connection\u003c\/li\u003e\n\u003cli\u003eIntegrated M48x0.75 thread for 2\" filters\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 2.5\" F\/3.9 Full Frame Reducer for FRA400 and FRA500\u003c\/h2\u003e\n\u003cp\u003eThe Askar 2.5\" F\/3.9 Full Frame Reducer transforms your Askar FRA400 or FRA500 astrograph into a significantly faster imaging system, achieving a final focal ratio of f\/3.9 with its 0.7x reduction factor. This 3-element, air-spaced optical design illuminates a full 44mm image circle, providing edge-to-edge sharpness on full-frame sensors while maintaining a standard 55mm back focus for straightforward integration of your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e0.7x Reduction for an f\/3.9 System\u003c\/h3\u003e\n\u003cp\u003eBy shortening the effective focal length of your telescope, this reducer dramatically increases the speed of your optical system. On an Askar FRA400, the focal length is reduced from 400mm to just 280mm, changing the native f\/5.6 ratio to a swift f\/3.9. This speed increase allows you to capture the same amount of signal in roughly half the time, maximizing your data acquisition during short imaging windows.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA 44mm Corrected Image Circle for Full-Frame Sensors\u003c\/h3\u003e\n\u003cp\u003eEngineered specifically for large-format sensors, this reducer delivers a fully-corrected 44mm image circle. This ensures that you can utilize the entire field of view of your full-frame DSLR, mirrorless, or dedicated astronomy camera without significant vignetting or loss of star quality at the corners. It turns your astrograph into a true wide-field instrument capable of capturing vast nebulae and star fields in a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Back Focus and Integrated 2\" Filter Threads\u003c\/h3\u003e\n\u003cp\u003eAskar designed this reducer for seamless integration into modern imaging setups. It features the industry-standard 55mm back focus, allowing you to connect most cameras and filter wheels with standard adapters. An integrated M48x0.75 thread at the front of the reducer provides a secure attachment point for any 2\" filter, enabling the use of light pollution or narrowband filters without adding complexity to your optical train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Askar F\/3.9 reducer do for my FRA400 or FRA500?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis 0.7x reducer shortens your telescope's focal length, making it optically \"faster.\" For the FRA400, it changes the focal length to 280mm and the focal ratio to f\/3.9. This results in a wider field of view and significantly shorter exposure times needed to capture faint deep-sky objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use full-frame cameras with the Askar F\/3.9 reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer is specifically designed to produce a corrected \u003cstrong\u003e44mm image circle\u003c\/strong\u003e, which is large enough to cover standard full-frame sensors (typically 43.3mm diagonal) without vignetting. This ensures sharp stars across the entire frame of your large-format camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs it difficult to connect my camera to the Askar F\/3.9 reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, connection is straightforward. The reducer requires a standard \u003cstrong\u003e55mm back focus\u003c\/strong\u003e from the rear mounting flange to your camera sensor. This is the same spacing used by most DSLRs with a T-ring and many dedicated astronomy cameras with their included spacers, making it easy to achieve the correct distance for optimal performance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does a 0.7x reducer affect my exposure times?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA faster focal ratio gathers light more quickly. Moving from f\/5.6 (on the FRA400) to f\/3.9 means your exposure times can be cut by more than half to achieve the same image brightness. A 5-minute sub-exposure at f\/5.6 is roughly equivalent to a 2.5-minute sub at f\/3.9.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I image the entire North America Nebula (NGC 7000) with an FRA400 and this reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this setup is ideal for such large targets. With the reducer, an FRA400 has a 280mm focal length. Paired with a full-frame sensor (like a Sony a7 series or ZWO ASI6200), this provides a field of view of approximately 7.3° x 4.9°, which is more than enough to comfortably frame the entire North America Nebula (NGC 7000) and the neighboring Pelican Nebula (IC 5070).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat's the best way to use 2\" filters with the Askar F\/3.9 reducer on my FRA500?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer features a built-in \u003cstrong\u003eM48x0.75 female thread\u003c\/strong\u003e on the telescope side. You can simply screw any standard 2\" mounted filter directly into the reducer before attaching it to your telescope. This places the filter in the optimal position within the light path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct\u003c\/td\u003e\n\u003ctd\u003eF\/3.9 Full Frame Reducer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eAskar FRA400, Askar FRA500\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.7x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/3.9\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e3-element, air-spaced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eM48 x 0.75 (for 2\" filters)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Outer Diameter\u003c\/td\u003e\n\u003ctd\u003e72mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 2.5\" F\/3.9 Full Frame Reducer\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":44967778976029,"sku":"ASK-ASKAR7256RD","price":384.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Askar-FRA400FR-1__39150.1610302783.1280.1280.jpg?v=1684345839"},{"product_id":"askar-3-f-3-9-full-frame-reducer-for-fra600","title":"Askar 3\" F\/3.9 Full Frame Reducer for FRA600","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces FRA600 focal ratio to F\/3.9\u003c\/li\u003e\n\u003cli\u003eDesigned for full-frame sensors\u003c\/li\u003e\n\u003cli\u003eMaintains a standard 55mm backfocus\u003c\/li\u003e\n\u003cli\u003eFeatures integrated M48 (2-inch) filter threads\u003c\/li\u003e\n\u003cli\u003e3-inch barrel for a secure connection\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 3\" F\/3.9 Full Frame Reducer for FRA600\u003c\/h2\u003e\n\u003cp\u003eDesigned exclusively for the Askar FRA600 astrograph, this 3\" full-frame reducer transforms the telescope into a significantly faster F\/3.9 optical system. By reducing the focal length, this corrector provides a much wider field of view and cuts down exposure times, maintaining a standard 55mm backfocus for easy camera integration.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTransform Your FRA600 into an F\/3.9 Astrograph\u003c\/h3\u003e\n\u003cp\u003eThis reducer converts your Askar FRA600 into a powerful, wide-field imaging instrument. The resulting F\/3.9 focal ratio allows you to gather significantly more light in a shorter period, enabling deeper exposures on faint nebulae and galaxies without taxing your mount's tracking accuracy over long sub-exposures. The wider field of view is essential for framing large-scale celestial objects in their entirety.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Backfocus and Full-Frame Illumination\u003c\/h3\u003e\n\u003cp\u003eEngineered for modern astrophotography, the reducer provides the industry-standard 55mm backfocus. This simplifies the process of connecting your full-frame DSLR, mirrorless, or dedicated astronomy camera, ensuring you can achieve perfect spacing with common M48 rings and accessories. Its optical design is optimized to fully illuminate a full-frame sensor, delivering sharp, well-corrected stars across the entire image. For added convenience, the reducer includes built-in M48x0.75 threads for easy installation of 2-inch filters into your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main benefit of using the Askar F\/3.9 reducer with my FRA600?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary benefit is speed. By converting your FRA600 to F\/3.9, you can dramatically shorten exposure times. This allows you to collect the same amount of data in less time, improving your efficiency and resulting in images with a higher signal-to-noise ratio. It also provides a wider field of view, perfect for large targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this Askar reducer maintain a flat field with full-frame sensors on the FRA600?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the Askar 3\" F\/3.9 reducer is specifically designed as a \"full frame\" corrector for the FRA600. Its multi-element optical system is engineered to deliver a flat, corrected field that illuminates large sensors, ensuring sharp stars from the center to the corners of your image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar F\/3.9 reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The reducer features integrated \u003cstrong\u003eM48x0.75 threads\u003c\/strong\u003e, which is the standard for 2-inch astronomy filters. You can directly screw in your favorite light pollution, narrowband, or LRGB filters without needing a separate filter drawer or wheel in some configurations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the backfocus of the Askar F\/3.9 reducer for the FRA600?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer is designed with a standard \u003cstrong\u003e55mm backfocus\u003c\/strong\u003e. This is measured from the rear flange of the reducer to the camera sensor. This standard distance makes it compatible with most dedicated astronomy cameras and DSLR\/mirrorless cameras when using the appropriate M48 T-ring.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Askar F\/3.9 reducer work with a camera and filter wheel combination on my FRA600?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, as long as your total imaging train length meets the 55mm backfocus requirement. You will need to account for the thickness of your filter wheel, off-axis guider (if any), and all adapters between the reducer and your camera's sensor. The standard 55mm spacing provides enough room for common accessory combinations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar F\/3.9 reducer help when imaging the Andromeda Galaxy (M31) with the FRA600?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Andromeda Galaxy (M31) is a very large target. The standard FRA600 might frame the core tightly, but this F\/3.9 reducer widens the field of view significantly. This allows you to capture the full expanse of M31, including its faint outer arms and satellite galaxies M32 and M110, all within a single, well-composed shot on a full-frame sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":44967779008797,"sku":"ASK-ASKAR656RD","price":615.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Askar-FRA600FR-1__09035.1610302990.1280.1280.jpg?v=1684345841"},{"product_id":"askar-0-7x-universal-reducer-for-107phq-130phq-151phq","title":"Askar 0.7x Universal Reducer for 107PHQ\/130PHQ\/151PHQ","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e0.7x Focal Reduction Factor\u003c\/li\u003e\n\u003cli\u003e44mm Full-Frame Image Circle\u003c\/li\u003e\n\u003cli\u003eMaintains a Standard 55mm Backfocus\u003c\/li\u003e\n\u003cli\u003e3-Element Air-Spaced Design with ED Glass\u003c\/li\u003e\n\u003cli\u003eOptimized for Askar 107PHQ, 130PHQ, and 151PHQ Telescopes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 0.7x Universal Reducer for 107PHQ\/130PHQ\/151PHQ\u003c\/h2\u003e\n\u003cp\u003eThe Askar 3” 0.7x Full-Frame Reducer transforms the 107PHQ, 130PHQ, and 151PHQ astrographs into faster, wider-field instruments perfect for deep-sky imaging. Its 3-element optical design incorporates ED glass to deliver a corrected 44mm image circle, while maintaining the industry-standard 55mm backfocus for easy integration with your existing camera and filter wheel setup. This reducer effectively shortens exposure times by increasing the light-gathering power of your f\/7 system to a rapid f\/4.9.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eFaster Imaging at f\/4.9: A 0.7x Triplet ED Reducer\u003c\/h3\u003e\n\u003cp\u003eBy reducing the native f\/7 focal ratio of the PHQ series telescopes to f\/4.9, this 0.7x reducer cuts required exposure times nearly in half. This allows you to gather more signal on faint targets in less time, maximizing your productivity during short imaging windows. The air-spaced triplet optical design, which includes one element of extra-low dispersion (ED) glass, ensures sharp, high-contrast images with excellent color correction across the field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eFull-Frame Coverage: A Corrected 44mm Image Circle\u003c\/h3\u003e\n\u003cp\u003eEngineered specifically for large-format sensors, this reducer illuminates a 44mm image circle. This is large enough to cover full-frame (36x24mm) CMOS and CCD sensors without vignetting, ensuring your entire frame is evenly lit from corner to corner. You can capture vast nebulae like the Veil Nebula complex or the Andromeda Galaxy (M31) in their entirety, without sacrificing image brightness or star quality at the edges of your frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSeamless Integration: 55mm Backfocus and Multi-Thread Adapters\u003c\/h3\u003e\n\u003cp\u003eAskar designed this reducer for straightforward integration into any standard imaging train. It provides a precise 55mm backfocus, the common standard for DSLRs, mirrorless cameras, and dedicated astronomy cameras with a filter wheel. The reducer includes M68, M54, and M48 thread adapters, giving you the flexibility to connect to virtually any focuser, off-axis guider, or camera system without needing to source additional parts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Askar 0.7x reducer do to the focal length of the Askar 130PHQ?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar 130PHQ has a native focal length of 1000mm at f\/7.7. The \u003cstrong\u003e0.7x reducer\u003c\/strong\u003e will shorten its focal length to 700mm and change the focal ratio to a much faster f\/5.4, allowing for wider fields of view and significantly shorter exposure times.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar 0.7x reducer compatible with full-frame cameras?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. It is designed to produce a corrected \u003cstrong\u003e44mm image circle\u003c\/strong\u003e, which is large enough to fully illuminate a standard full-frame sensor (36x24mm) without significant vignetting, providing sharp stars across the entire frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I connect my camera to the Askar 0.7x Universal Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer is designed for a standard \u003cstrong\u003e55mm backfocus\u003c\/strong\u003e from its rearmost flange. It includes M68, M54, and M48 adapters, allowing you to directly connect most dedicated astronomy cameras, DSLRs (with a standard 44mm T-ring), and filter wheels using common extension tubes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this reducer introduce chromatic aberration to my Askar 107PHQ?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The reducer features a \u003cstrong\u003e3-element optical design that includes one ED (Extra-low Dispersion) glass element\u003c\/strong\u003e. This design actively corrects for chromatic aberration, ensuring that the excellent color fidelity of the 107PHQ's quadruplet objective is maintained.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar 0.7x reducer help when imaging large targets like the North American Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOn a telescope like the Askar 151PHQ (1057mm focal length), the native field of view is too narrow to frame the entire North American Nebula. By reducing the focal length to approximately 740mm, the \u003cstrong\u003e0.7x reducer\u003c\/strong\u003e expands the field of view, allowing you to capture the entire nebula and the adjacent Pelican Nebula (IC 5070) in a single shot with a full-frame camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Askar 0.7x reducer for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis accessory is designed and optically corrected specifically for astrophotography. While you might be able to reach focus with some long-focal-length eyepieces, it is not optimized for visual use and will likely result in suboptimal views. Its primary purpose is to create a flat, corrected field for a camera sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.7x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescopes\u003c\/td\u003e\n\u003ctd\u003eAskar 107PHQ, 130PHQ, 151PHQ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e3-element air-spaced triplet with one ED element\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackfocus\u003c\/td\u003e\n\u003ctd\u003e55mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnection to Focuser\u003c\/td\u003e\n\u003ctd\u003e3-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput Thread Adapters\u003c\/td\u003e\n\u003ctd\u003eM68x1, M54x0.75, M48x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Diameter\u003c\/td\u003e\n\u003ctd\u003e80mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_2025_First_Half_Product_Collection_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":44968036466973,"sku":"ASK-ASF107130RE","price":538.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Askar-PHQ-Reducer__94249.1657565838.1280.1280.jpg?v=1684348170"},{"product_id":"askar-0-76x-reducer-for-80phq","title":"Askar 0.76x Reducer for 80PHQ","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e0.76x reduction factor specifically for the Askar 80PHQ\u003c\/li\u003e\n\u003cli\u003eReduces focal ratio from f\/7.5 to a faster f\/5.7\u003c\/li\u003e\n\u003cli\u003eCreates a new focal length of 456mm\u003c\/li\u003e\n\u003cli\u003eGenerates a 44mm image circle, fully illuminating full-frame sensors\u003c\/li\u003e\n\u003cli\u003eMaintains a standard 55mm backfocus for easy camera connection\u003c\/li\u003e\n\u003cli\u003eFeatures an integrated M48x0.75 filter thread\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 0.76x Reducer for 80PHQ\u003c\/h2\u003e\n\u003cp\u003eThis Askar 0.76x Reducer is engineered specifically for the 80PHQ astrograph, transforming its native f\/7.5 optics into a faster f\/5.7 imaging system with a 456mm focal length. The 3-element air-spaced triplet design delivers a corrected 44mm image circle, fully illuminating full-frame sensors while maintaining a standard 55mm backfocus for straightforward integration with your camera and filter wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA Triplet Design for f\/5.7 Speed and a 456mm Focal Length\u003c\/h3\u003e\n\u003cp\u003eBy decreasing the focal ratio of the 80PHQ from f\/7.5 to f\/5.7, this 0.76x reducer shortens required exposure times by approximately 42%, allowing you to capture more signal in less time. The resulting 456mm focal length provides a wider field of view, ideal for framing large nebulae and star clusters. The internal 3-element triplet lens configuration ensures that the wider field remains sharp and well-corrected across the frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eFull-Frame Imaging: 44mm Image Circle and Standard 55mm Backfocus\u003c\/h3\u003e\n\u003cp\u003eThe reducer is designed to produce a 44mm image circle, providing full, unvignetted illumination for cameras with full-frame (36x24mm) sensors. It connects directly to the 80PHQ's focuser and features a standard 55mm backfocus, simplifying the process of attaching a DSLR, mirrorless, or dedicated astronomy camera with the correct spacing. An integrated M48x0.75 (2-inch) filter thread allows you to easily add light pollution or narrowband filters into your imaging train without needing a separate filter drawer.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Askar 0.76x Reducer do for my 80PHQ telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar 0.76x Reducer converts your Askar 80PHQ from its native f\/7.5 focal ratio to a faster \u003cstrong\u003ef\/5.7\u003c\/strong\u003e. This shortens your exposure times and provides a wider field of view with a new focal length of \u003cstrong\u003e456mm\u003c\/strong\u003e, making it better suited for capturing large deep-sky objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 44mm image circle of this reducer large enough for my full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The \u003cstrong\u003e44mm image circle\u003c\/strong\u003e is specifically designed to be larger than the diagonal of a standard full-frame sensor (which is approximately 43.3mm). This ensures your full-frame camera sensor is fully illuminated without vignetting caused by the reducer.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I connect my camera to the Askar 0.76x Reducer for the 80PHQ?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer provides a standard \u003cstrong\u003e55mm backfocus\u003c\/strong\u003e from its rearmost thread. This is the standard spacing for most cooled astronomy cameras when used with a filter wheel, or for a DSLR\/mirrorless camera with its corresponding M48 T-ring. You simply add the necessary M48 spacers to achieve the 55mm distance to your camera's sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-Q\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the f\/5.7 speed help when imaging the Andromeda Galaxy (M31) with the 80PHQ?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Andromeda Galaxy (M31) is a very large target that benefits from the wider \u003cstrong\u003e456mm focal length\u003c\/strong\u003e. More importantly, the faster \u003cstrong\u003ef\/5.7\u003c\/strong\u003e optics gather light more quickly than the native f\/7.5, allowing you to capture the faint outer arms and dust lanes of the galaxy with shorter individual exposures, improving your overall signal-to-noise ratio in a single imaging session.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use filters with the Askar 0.76x reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer has a built-in \u003cstrong\u003eM48x0.75 (2-inch) filter thread\u003c\/strong\u003e on the camera side, allowing you to easily screw in standard 2-inch mounted filters for light pollution reduction or narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 0.76x reducer work on telescopes other than the Askar 80PHQ?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this reducer is specifically designed and optically matched to work with the Askar 80PHQ astrograph. Using it on other telescopes will likely result in poor optical correction, field curvature, and an inability to reach focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReducer Type\u003c\/td\u003e\n\u003ctd\u003e0.76x Focal Reducer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescope\u003c\/td\u003e\n\u003ctd\u003eAskar 80PHQ\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting Focal Length\u003c\/td\u003e\n\u003ctd\u003e456mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e3-element, air-spaced triplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 (2-inch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Outer Diameter\u003c\/td\u003e\n\u003ctd\u003e68mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 0.76x Reducer for 80PHQ\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":44968076083485,"sku":"ASK-ASKAR80R","price":368.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Askar-80PHQ-Reducer__01912.1679584601.1280.1280.jpg?v=1684348743"},{"product_id":"askar-1x-field-flattener-for-103apo","title":"Askar 1x Field Flattener for 103APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eCorrects field curvature and coma for the Askar 103APO\u003c\/li\u003e\n\u003cli\u003eMaintains the native 700.4mm focal length and f\/6.8 ratio\u003c\/li\u003e\n\u003cli\u003eTriplet optical design delivers sharp stars edge-to-edge\u003c\/li\u003e\n\u003cli\u003eProvides a 44mm full-frame corrected image circle\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus from the M48 thread\u003c\/li\u003e\n\u003cli\u003eIncludes M54 and M48 camera adapters and a 2\" filter thread\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 1x Field Flattener for 103APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar 1x Field Flattener is engineered specifically for the 103APO refractor, correcting field curvature across a 44mm full-frame image circle while maintaining the telescope's native 700.4mm focal length and f\/6.8 focal ratio. This 0.58kg flattener utilizes a triplet optical design to deliver sharp stars to the edge of the frame and integrates into any standard imaging train with 55mm of back focus from its M48 male thread.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA 44mm Flat Field for the Askar 103APO\u003c\/h3\u003e\n\u003cp\u003eThis flattener's primary function is to eliminate the field curvature and coma inherent in a refracting telescope, ensuring star points remain perfectly round across the entire sensor. The triplet air-spaced lens design achieves this correction over a 44mm image circle, making it an essential accessory for imagers using full-frame DSLR, mirrorless, or dedicated astronomy cameras with the Askar 103APO.\u003c\/p\u003e\n\u003cp\u003eBy using a 1x magnification factor, the flattener preserves the telescope's native 700.4mm focal length and f\/6.8 focal ratio. This allows you to capture wide-field targets with the maximum resolution and light-gathering power the 103APO optics can provide, but with the critical addition of a perfectly flat field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Back Focus and Standardized Connections\u003c\/h3\u003e\n\u003cp\u003eAskar designed this flattener for seamless integration into modern imaging setups. It provides the industry-standard 55mm of back focus measured from the base of its male M48x0.75 thread, which simplifies connecting most cameras and filter wheels without complex calculations. Simply add your camera's T-ring or standard spacers to reach the 55mm distance for optimal performance.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVersatile Adapters:\u003c\/strong\u003e The camera side includes both M54×0.75 and M48×0.75 threaded adapters, providing direct attachment for a wide range of cameras, filter drawers, and off-axis guiders.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Filter Cell:\u003c\/strong\u003e A built-in M48x0.75 thread inside the adapter acts as a 2-inch filter cell, allowing you to mount light pollution or narrowband filters directly within the flattener itself.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRobust Build:\u003c\/strong\u003e The entire housing is CNC-machined for precise optical alignment and weighs a solid 0.58kg, ensuring no flexure in the imaging train.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main purpose of the Askar 1x Flattener for the 103APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar 1x Flattener is designed to correct optical aberrations like \u003cstrong\u003efield curvature\u003c\/strong\u003e and \u003cstrong\u003ecoma\u003c\/strong\u003e in the Askar 103APO telescope. This ensures that stars are sharp and point-like across the entire imaging sensor, which is crucial for astrophotography, especially with large-format cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Askar 1x Flattener change the 103APO's focal length?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. As a \u003cstrong\u003e1x flattener\u003c\/strong\u003e, it does not reduce or extend the focal length. When attached to the Askar 103APO, the telescope maintains its native \u003cstrong\u003e700.4mm focal length\u003c\/strong\u003e and \u003cstrong\u003ef\/6.8 focal ratio\u003c\/strong\u003e, simply delivering a corrected, flat field of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat cameras are compatible with the Askar 1x Flattener's 55mm back focus?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe standard \u003cstrong\u003e55mm back focus\u003c\/strong\u003e is compatible with most imaging systems. This includes:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eDSLR and mirrorless cameras with a standard T-ring adapter.\u003c\/li\u003e\n\u003cli\u003eDedicated astronomy cameras when combined with the appropriate spacers to achieve the 55mm distance.\u003c\/li\u003e\n\u003c\/ul\u003e\nThe flattener includes both M54 and M48 threads to connect to a wide variety of accessories.\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar 1x Flattener for the 103APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Askar 1x Flattener has a built-in \u003cstrong\u003eM48x0.75 filter thread\u003c\/strong\u003e on the camera side. This allows you to directly screw in standard 2-inch astronomy filters for light pollution suppression or narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar 1x Flattener improve images of the Andromeda Galaxy (M31) with the 103APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA large target like the Andromeda Galaxy (M31) will stretch across the entire field of a full-frame sensor when imaged with the Askar 103APO. Without this flattener, stars at the edges of the galaxy would appear elongated or out of focus. The \u003cstrong\u003eAskar 1x Flattener\u003c\/strong\u003e ensures that the outer spiral arms and surrounding star fields of M31 are just as sharp as the galactic core.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Askar 1x Flattener fully illuminate my full-frame sensor on an f\/6.8 system?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The flattener is specifically designed to produce a corrected and illuminated \u003cstrong\u003e44mm image circle\u003c\/strong\u003e. This is large enough to cover a standard full-frame sensor (which has a 43.3mm diagonal) without vignetting, making it a perfect match for the Askar 103APO's f\/6.8 optics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e3-Element Air-Spaced (Triplet)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMagnification\u003c\/td\u003e\n\u003ctd\u003e1x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescope\u003c\/td\u003e\n\u003ctd\u003eAskar 103APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length with 103APO\u003c\/td\u003e\n\u003ctd\u003e700.4mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio with 103APO\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Image Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from M48x0.75 male thread base)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera-Side Threads\u003c\/td\u003e\n\u003ctd\u003eM54x0.75 \u0026amp; M48x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Filter Threads\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 (2-inch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.58 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_103APO_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":46861263405341,"sku":"ASK-ASKFL10310","price":307.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-103APO-Field-Flattener-ASKFL10310-1.png?v=1697487604"},{"product_id":"askar-0-8x-reducer-for-103apo","title":"Askar 0.8x Reducer for 103APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces telescope focal ratio to a faster f\/5.44\u003c\/li\u003e\n\u003cli\u003eShortens 103APO focal length to 560.32mm for wider fields\u003c\/li\u003e\n\u003cli\u003eTriplet optical design provides field flattening\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus for easy camera connection\u003c\/li\u003e\n\u003cli\u003eIntegrated M48x0.75 threads for 2\" filters\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 0.8x Reducer for 103APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar 0.8x Reducer is engineered specifically for the Askar 103APO, transforming it into a faster f\/5.44 imaging system and shortening its focal length to 560.32mm for wider fields of view. This triplet reducer maintains a standard 55mm back focus from its M48 thread and weighs just 0.48kg, adding minimal load to the focuser while significantly increasing light-gathering speed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet Optics: A Faster f\/5.44 System for the 103APO\u003c\/h3\u003e\n\u003cp\u003eBy reducing the 103APO's native focal ratio to f\/5.44, this corrector significantly cuts down required exposure times, allowing you to capture more signal on faint targets in a single session. The triplet optical design also acts as a field flattener, ensuring sharp, point-like stars across a full-frame sensor, which is critical when imaging expansive targets like the North American Nebula (NGC 7000) or the Heart and Soul Nebulae (IC 1805 and IC 1848).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eMechanical Connectivity: 55mm Back Focus for Standardized Imaging Trains\u003c\/h3\u003e\n\u003cp\u003eThis reducer is designed for straightforward integration into your existing setup. It provides the industry-standard 55mm of back focus from the base of its M48 male thread, simplifying the connection of DSLRs (with a standard T-ring) and dedicated astronomy cameras with filter wheels and off-axis guiders. The rear of the reducer includes both M54×0.75 and M48×0.75 adapters, and a built-in M48×0.75 thread allows for direct installation of 2-inch filters without adding extra spacing components.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Askar 0.8x Reducer do for my 103APO telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Askar 0.8x Reducer shortens the focal length of your 103APO to \u003cstrong\u003e560.32mm\u003c\/strong\u003e and increases its speed to \u003cstrong\u003ef\/5.44\u003c\/strong\u003e. This provides a wider field of view, allowing you to fit larger celestial objects into your frame, and reduces exposure times, enabling you to collect data on faint nebulae and galaxies more efficiently.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I connect my camera to the Askar 103APO 0.8x Reducer to achieve the correct 55mm back focus?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer provides \u003cstrong\u003e55mm of back focus\u003c\/strong\u003e from the base of the included M48 male adapter thread. To achieve this spacing, you simply add extension tubes or accessories between the reducer and your camera sensor until the total distance is 55mm. A typical DSLR with a T-ring already has approximately 55mm of spacing, making the connection direct.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar 103APO 0.8x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer features an integrated \u003cstrong\u003eM48x0.75 female thread\u003c\/strong\u003e on the camera side, which is the standard for 2-inch astronomy filters. You can thread your filters directly into the reducer for light pollution suppression or narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar 103APO 0.8x Reducer suitable for planetary imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile technically usable, a reducer is not ideal for planetary imaging. Reducers decrease focal length to capture wider fields, which is the opposite of the high magnification needed to resolve detail on planets like Jupiter and Saturn. For planetary work, you should use the Askar 103APO at its native focal length or with a Barlow lens to increase magnification.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar 103APO 0.8x Reducer improve imaging of large targets like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAt its native focal length, the Askar 103APO may be too narrow to frame the entire Andromeda Galaxy (M31) and its satellite galaxies with a larger sensor. By reducing the focal length to \u003cstrong\u003e560.32mm\u003c\/strong\u003e, the reducer widens the field of view, allowing you to capture the full galactic structure in a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this reducer provide a flat field for my full-frame DSLR or CMOS camera on the Askar 103APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the \u003cstrong\u003etriplet\u003c\/strong\u003e optical design of the Askar 0.8x Reducer is engineered to provide field flattening that illuminates a full-frame sensor. This ensures that stars remain sharp and round from the center of your image all the way to the corners, which is essential for creating high-quality astrophotographs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.8x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinal Focal Length (on 103APO)\u003c\/td\u003e\n\u003ctd\u003e560.32mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinal Focal Ratio (on 103APO)\u003c\/td\u003e\n\u003ctd\u003ef\/5.44\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from M48 thread base)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.48 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear-End Threads\u003c\/td\u003e\n\u003ctd\u003eM54×0.75, with M48×0.75 adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Threads\u003c\/td\u003e\n\u003ctd\u003eM48×0.75 (for 2\" filters)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_103APO_0.8x_Reducer_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":46861341458717,"sku":"ASK-ASKRE10308","price":307.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-103APO-0-8x-Reducer-ASKRE10308-1.png?v=1697488015"},{"product_id":"askar-0-6x-reducer-for-103apo","title":"Askar 0.6x Reducer for 103APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eTransforms Askar 103APO to an f\/4.08, 420.24mm focal length system\u003c\/li\u003e\n\u003cli\u003eQuadruplet optical design provides field flattening for full-frame sensors\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus for easy camera and accessory integration\u003c\/li\u003e\n\u003cli\u003eIncludes M68, M54, and M48 adapters for versatile camera connection\u003c\/li\u003e\n\u003cli\u003eIntegrated M48x0.75 thread for use with 2\" filters\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 0.6x Reducer for 103APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar 0.6x Reducer for 103APO transforms the telescope into a fast f\/4.08 astrograph, shortening the focal length to 420.24mm for capturing vast celestial targets. This dedicated quadruplet reducer is optically matched to the 103APO, delivering a flat field and maintaining sharp stars from edge to edge while adhering to a standard 55mm back focus distance for your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTransforming the 103APO to an f\/4.08 Astrograph\u003c\/h3\u003e\n\u003cp\u003eBy reducing the native focal ratio to f\/4.08, this accessory dramatically cuts required exposure times, allowing you to gather more signal in less time. The quadruplet optical design not only reduces the focal length but also acts as a field flattener, correcting for optical aberrations and ensuring pinpoint stars across a wide, flat image circle suitable for full-frame cameras. At a focal length of 420.24mm, you can frame large emission nebulae like the North American Nebula (NGC 7000) or the entire Andromeda Galaxy (M31) with ease.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA Detachable-Tube Design for f\/4 Speed\u003c\/h3\u003e\n\u003cp\u003eAchieving this faster focal ratio requires a unique mechanical integration with the Askar 103APO. To use the 0.6x reducer, you must detach the rear section of the main telescope tube, effectively shortening the instrument to achieve focus. This purpose-built design ensures perfect spacing and optical alignment. The reducer itself adds 0.98kg to your imaging setup, a factor to consider when balancing your mount for precise tracking.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Back Focus with M48, M54, and M68 Adapters\u003c\/h3\u003e\n\u003cp\u003eThe Askar 0.6x Reducer simplifies camera connection by using the industry-standard 55mm back focus distance from the base of its M48 male thread. This compatibility works seamlessly with most DSLRs (with a standard T-ring) and dedicated astronomy cameras. For maximum flexibility, the reducer includes a set of adapters for M68×1, M54×0.75, and M48×0.75 threads, ensuring you can connect a wide variety of cameras, filter wheels, and off-axis guiders. The M48 adapter also features an internal thread for mounting 2-inch filters directly.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 0.6x reducer change the Askar 103APO's imaging characteristics?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt transforms the Askar 103APO into a faster, wider-field instrument. The focal ratio is reduced to \u003cstrong\u003ef\/4.08\u003c\/strong\u003e and the focal length to \u003cstrong\u003e420.24mm\u003c\/strong\u003e. This allows for significantly shorter exposure times and the ability to frame much larger deep-sky objects in a single shot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need to modify my Askar 103APO to use this 0.6x reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Askar 103APO features a detachable tube design specifically for this reducer. You must remove the rear section of the optical tube to shorten the telescope, which allows the reducer to reach focus and function correctly. This is a required step for proper installation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the correct back focus for the Askar 103APO 0.6x reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe required back focus is a standard \u003cstrong\u003e55mm\u003c\/strong\u003e. This distance is measured from the base of the M48 male thread on the reducer to your camera's sensor. Most dedicated astronomy cameras and DSLR\/mirrorless cameras with T-rings are designed around this standard distance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2\" filters with the Askar 103APO 0.6x reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The included M48 adapter has an internal \u003cstrong\u003eM48×0.75 thread\u003c\/strong\u003e, which allows you to screw in standard 2-inch astronomy filters directly. This is ideal for adding light pollution or narrowband filters to your imaging train without needing a separate filter drawer or wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Askar 103APO 0.6x reducer help when imaging the North American Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe North American Nebula is a very large target, spanning several degrees of the sky. The reducer's \u003cstrong\u003e420.24mm\u003c\/strong\u003e focal length provides a much wider field of view than the native 103APO, allowing you to capture the entire nebula and the adjacent Pelican Nebula (IC 5070) in a single frame with most full-frame or APS-C sensors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the f\/4.08 speed from this Askar reducer beneficial for imaging broadband targets like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The fast \u003cstrong\u003ef\/4.08\u003c\/strong\u003e focal ratio gathers light much more quickly than the native telescope. When imaging a broadband target like M31, this means you can capture faint outer dust lanes and details with shorter individual sub-exposures, improving your signal-to-noise ratio and reducing the impact of tracking errors or changing sky conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eQuadruplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.6x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Length (103APO)\u003c\/td\u003e\n\u003ctd\u003e420.24mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Ratio (103APO)\u003c\/td\u003e\n\u003ctd\u003ef\/4.08\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from base of M48 thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connection Threads\u003c\/td\u003e\n\u003ctd\u003eM68×1, M54×0.75, M48×0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eM48×0.75 (internal)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.98kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_103APO_0.6x_Reducer_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":46861375701277,"sku":"ASK-ASKRE10306","price":461.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-103APO-0-6x-Reducer-ASKRE10306-1.png?v=1697488274"},{"product_id":"askar-0-8x-reducer-for-140apo","title":"Askar 0.8x Reducer for 140APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces 140APO Focal Ratio to f\/5.6\u003c\/li\u003e\n\u003cli\u003eShortens 140APO Focal Length to 784mm\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus Requirement\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design with Field Flattening\u003c\/li\u003e\n\u003cli\u003eIntegrated M48 (2-inch) Filter Thread\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 0.8x Reducer for 140APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar 0.8x Reducer for 140APO converts the telescope into a faster f\/5.6 imaging system with a 784mm focal length. This triplet reducer is engineered to maintain a standard 55mm back focus from its M48 male thread, simplifying camera connections. The 0.63kg assembly includes both M54×0.75 and M48×0.75 rear threads, with an integrated M48 filter thread inside for direct filter installation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTransforming the 140APO to an f\/5.6 Astrograph\u003c\/h3\u003e\n\u003cp\u003eBy reducing the native focal ratio of the Askar 140APO to f\/5.6, this corrector significantly cuts required exposure times, allowing you to gather more signal in less time. The triplet optical design simultaneously flattens the field for sharp stars across a full-frame sensor, while the shorter 784mm focal length provides a wider field of view for framing large targets like the Andromeda Galaxy (M31) or the North America Nebula (NGC 7000).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Back Focus and Flexible Connectivity\u003c\/h3\u003e\n\u003cp\u003eIntegrating the reducer into your imaging train is straightforward, thanks to the industry-standard 55mm back focus measured from the base of the M48 male thread. The reducer provides both M54×0.75 and M48×0.75 output threads for direct connection to a range of cameras and filter wheels. For added convenience, an internal M48×0.75 filter thread allows you to install 2-inch filters directly into the reducer itself, minimizing the components in your optical path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar 0.8x Reducer change my field of view on the 140APO when imaging the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer shortens the 140APO's focal length to \u003cstrong\u003e784mm\u003c\/strong\u003e, widening your field of view significantly. This allows you to capture the entire Orion Nebula complex, from the Trapezium Cluster to the fainter outer loops, in a single frame with a full-frame camera, which is difficult at the native focal length.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI use an APS-C camera with my Askar 140APO. Is this reducer still a good choice?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While designed to illuminate a full-frame sensor, the 0.8x Reducer provides excellent field flattening for smaller APS-C sensors. The main benefit is the speed increase to \u003cstrong\u003ef\/5.6\u003c\/strong\u003e, which reduces your sub-exposure times regardless of sensor size, helping to improve your signal-to-noise ratio on faint targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the back focus for the Askar 140APO 0.8x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe required back focus is a standard \u003cstrong\u003e55mm\u003c\/strong\u003e, measured from the base of the male M48x0.75 thread to your camera's sensor. This is compatible with most DSLR\/mirrorless cameras using a standard T-ring and many dedicated astronomy cameras with their included spacers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar 0.8x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the reducer has a built-in \u003cstrong\u003eM48x0.75 filter thread\u003c\/strong\u003e on the camera side. This allows you to screw a standard 2-inch filter directly into the reducer housing, placing it securely within the optical path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does this reducer attach to the Askar 140APO telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer is designed to thread directly onto the focuser of the Askar 140APO for a secure, tilt-free connection, ensuring perfect optical alignment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the optical design of the Askar 140APO 0.8x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer uses a \u003cstrong\u003etriplet (3-element)\u003c\/strong\u003e air-spaced optical design. This configuration allows it to both reduce the focal length and correct for field curvature, providing sharp stars across the entire image field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Length\u003c\/td\u003e\n\u003ctd\u003e784mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Side Threads\u003c\/td\u003e\n\u003ctd\u003eM54×0.75 \u0026amp; M48×0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Filter Threads\u003c\/td\u003e\n\u003ctd\u003eM48×0.75 (2-inch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.63 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 0.8x Reducer for 140APO\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eFront Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eRear Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_140APO_0.8x_Reducer_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":47636055032093,"sku":"ASK-ASKAR140R","price":461.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/7aa725af-9cf7-4e43-9110-3003e039fd08_1ac241f4-f6d7-4ae3-b7b3-93ea3908ef1e.jpg?v=1722021035"},{"product_id":"askar-1x-field-flattener-for-140apo","title":"Askar 1x Field Flattener for 140APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eEngineered for the Askar 140APO Triplet Refractor\u003c\/li\u003e\n\u003cli\u003e1x Flattener Preserves Native f\/7 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eCorrects a 44mm Full-Frame Image Circle\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus Requirement\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design for Sharp, Coma-Free Stars\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 1x Field Flattener for 140APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar 1x Field Flattener is engineered specifically for the Askar 140APO refractor, maintaining the native 980mm focal length and f\/7 focal ratio of the telescope. Its triplet optical design corrects for field curvature across a 44mm full-frame image circle and establishes a standard 55mm back focus for seamless integration with your existing imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet Optics for a 44mm Corrected Image Circle\u003c\/h3\u003e\n\u003cp\u003eRefractor optics naturally produce a curved focal plane, resulting in elongated stars at the corners of an image. This 1x flattener uses a three-element, air-spaced triplet lens system to counteract this effect, ensuring pinpoint stars across the entire field of a full-frame sensor. By supporting a 44mm image circle, you can leverage large-format CMOS and CCD cameras without significant vignetting or distortion at the edges.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Back Focus and Flexible Camera Connections\u003c\/h3\u003e\n\u003cp\u003eDesigned for straightforward integration, this flattener requires a standard 55mm back focus from the base of its M48 male thread. This spacing is compatible with most ZWO, QHY, and other dedicated astronomy cameras when used with their stock adapters, as well as with standard DSLR\/mirrorless T-rings. The 0.79kg unit provides multiple camera-side connections, including M68×1, M54×0.75, and M48×0.75 threads, and features internal M48 threads for mounting 2-inch filters within the optical path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the Askar 1x Field Flattener for the 140APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIts primary purpose is to correct the natural field curvature of the Askar 140APO refractor. This correction ensures that stars are sharp and round not just in the center of your image, but all the way to the corners, which is essential for astrophotography with modern large-format sensors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this Askar flattener change the focal length of my 140APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. This is a \u003cstrong\u003e1x flattener\u003c\/strong\u003e, meaning it does not reduce or extend the focal length. When attached to the Askar 140APO, the telescope's focal length remains 980mm and the focal ratio stays at f\/7.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar 1x flattener improve images of the Andromeda Galaxy (M31) with the 140APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA large target like the Andromeda Galaxy (M31) will fill the frame of a full-frame sensor on the 140APO. Without the flattener, stars in the outer arms and surrounding the galaxy would appear stretched. With the flattener's 44mm corrected circle, the entire galaxy and its surrounding starfield will be rendered with sharp, pinpoint stars from edge to edge.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I achieve the correct 55mm back focus with the Askar 1x Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 55mm distance is measured from the base of the flattener's M48 male thread to your camera's sensor. Most dedicated astronomy cameras and DSLR\/mirrorless cameras with a T-ring are designed to meet this 55mm standard using a combination of included extension rings. You must ensure your total imaging train (off-axis guider, filter wheel, etc.) adds up to exactly 55mm for optimal performance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2\" filters with the Askar 140APO flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The flattener has a built-in M48×0.75 filter thread on the telescope side of the camera adapters. This allows you to directly screw in any standard 2-inch astronomy filter for light pollution reduction or narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Askar 1x flattener work on telescopes other than the 140APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this flattener is optically matched specifically for the Askar 140APO triplet refractor. Using it with other telescopes will likely result in poor field correction and degraded image quality. For other telescopes, you should use the flattener designed for that specific optical system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003e3-Element Triplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMagnification\u003c\/td\u003e\n\u003ctd\u003e1x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescope\u003c\/td\u003e\n\u003ctd\u003eAskar 140APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length (with 140APO)\u003c\/td\u003e\n\u003ctd\u003e980mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio (with 140APO)\u003c\/td\u003e\n\u003ctd\u003ef\/7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Image Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connections\u003c\/td\u003e\n\u003ctd\u003eM68×1, M54×0.75, M48×0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eInternal M48×0.75 (for 2\" filters)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.79kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_140APO_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":47636067615005,"sku":"ASK-ASKAR140FL","price":461.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/4930810f-9de1-46ee-a4ba-28f63ecc8ddd.png?v=1722023524"},{"product_id":"askar-0-75x-71f-reducer","title":"Askar 0.75x 71F Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e0.75x Reduction Factor\u003c\/li\u003e\n\u003cli\u003eTransforms Askar 71F to f\/5.2\u003c\/li\u003e\n\u003cli\u003eNew Focal Length: 369mm\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 0.75x 71F Reducer\u003c\/h2\u003e\n\u003cp\u003eThe Askar 0.75x 71F Reducer transforms the Askar 71F refractor into a faster f\/5.2 imaging system with a new focal length of 369mm. This triplet reducer provides a standard 55mm back focus for easy camera integration and weighs just 0.23kg.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA Faster Askar 71F: The 0.75x Reduction to f\/5.2\u003c\/h3\u003e\n\u003cp\u003eBy reducing the native focal ratio of the Askar 71F to f\/5.2, this corrector significantly shortens required exposure times, allowing you to gather more signal on faint targets in a single session. The resulting 369mm focal length creates a wider field of view, ideal for framing large emission nebulae like the North American Nebula (NGC 7000) or sprawling star clusters. Its triplet optical design is engineered specifically to maintain image sharpness across the field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eFull-Frame Correction with 55mm Standard Back Focus\u003c\/h3\u003e\n\u003cp\u003eThis reducer is also a dedicated field flattener, designed to produce sharp stars out to the corners of full-frame sensors. Imaging integration is straightforward thanks to a standard 55mm back focus, measured from the base of its M48 male thread, simplifying connection to your DSLR or dedicated astronomy camera. The design also incorporates threads for standard 2-inch filters, allowing you to use light pollution or narrowband filters without adding extra spacing to your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main benefit of using the Askar 0.75x Reducer with my 71F telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary benefit is speed. It reduces the focal ratio to f\/5.2, which cuts your exposure times significantly compared to the native f\/7 ratio. This allows you to collect more data on faint objects in less time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I connect my camera to the Askar 71F 0.75x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer provides a standard \u003cstrong\u003e55mm back focus\u003c\/strong\u003e from the base of its M48 male thread. You will need to use a combination of M48 spacers and adapters to place your camera's sensor at exactly this distance to achieve a flat field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs this Askar 0.75x reducer suitable for imaging the Andromeda Galaxy (M31) with a full-frame camera on the 71F?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reduced focal length of \u003cstrong\u003e369mm\u003c\/strong\u003e provides a wide field of view that is excellent for large targets like the Andromeda Galaxy (M31) or the Heart and Soul Nebulae. The reducer is designed to flatten the field for full-frame sensors, ensuring sharp stars across the entire frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Askar 0.75x 71F Reducer also work as a field flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it is a reducer-flattener. Its \u003cstrong\u003etriplet optical design\u003c\/strong\u003e corrects for field curvature, ensuring that stars are sharp from the center to the edges of the image, which is critical for astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar 0.75x Reducer on my 71F?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer's connection system is designed to accommodate standard 2-inch (M48x0.75) filters. You can thread them directly into the imaging train, making it easy to use narrowband or light pollution filters for targets like the Orion Nebula (M42).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the image circle of the Askar 0.75x 71F Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer is designed as a full-frame corrector. It effectively illuminates and flattens the field for camera sensors up to a 35mm format (43mm diagonal), making it compatible with a wide range of DSLRs and dedicated astronomy cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.75x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Length (with 71F)\u003c\/td\u003e\n\u003ctd\u003e369mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Ratio (with 71F)\u003c\/td\u003e\n\u003ctd\u003ef\/5.2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from the base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear Thread\u003c\/td\u003e\n\u003ctd\u003eM59*1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.23kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 0.75x 71F Reducer\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software \u0026amp; Drivers\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":49200895263005,"sku":"ASK-ASKAR71R","price":291.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-Reducer-71F-1.jpg?v=1727375509"},{"product_id":"askar-1x-field-flattener-for-103apo-copy","title":"Askar 1x Field Flattener for 120APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDesigned specifically for the Askar 120APO Telescope\u003c\/li\u003e\n\u003cli\u003e1x Magnification Factor\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design\u003c\/li\u003e\n\u003cli\u003eMaintains Native f\/7 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus\u003c\/li\u003e\n\u003cli\u003eWeighs 0.75kg\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 1x Field Flattener for 120APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar 1x Field Flattener for the 120APO is a dedicated triplet corrector that maintains the telescope's native 840mm focal length and f\/7 focal ratio. It establishes a standard 55mm back focus from its M48 male thread, ensuring compatibility with common imaging trains. Weighing 0.75kg, it provides robust optical correction without significantly altering the instrument's balance.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet Optics: Correcting the 120APO's f\/7 Field Edge-to-Edge\u003c\/h3\u003e\n\u003cp\u003eThis 1x flattener is engineered specifically for the Askar 120APO, using a triplet optical design to eliminate field curvature and coma across large imaging sensors. By maintaining the telescope's native f\/7 focal ratio, it prevents any change in image scale or exposure times. The result is a perfectly flat field, rendering stars as sharp points from the center to the corners of a full-frame sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eMechanical Design: 55mm Back Focus and Integrated Filter Threads\u003c\/h3\u003e\n\u003cp\u003eIntegration into your imaging train is straightforward, with a standard 55mm back focus measured from the base of the M48 male thread. The camera side includes both M54x0.75 and M48x0.75 adapters, and the M48 adapter features internal threads for 2-inch filters, allowing you to add light pollution or narrowband filters without extra spacers. The entire 0.75kg housing is CNC-machined for precise alignment and includes threaded metal caps for protection.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Askar 1x Flattener change the focal length of the 120APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. As a 1x flattener, it is designed to maintain the Askar 120APO's native 840mm focal length and f\/7 focal ratio. It corrects for field curvature without altering the image scale.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the back focus for the Askar 120APO 1x Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe required back focus is a standard \u003cstrong\u003e55mm\u003c\/strong\u003e, measured from the base of the male M48x0.75 thread on the included adapter. This simplifies connecting most DSLRs (with a T-ring) and dedicated astronomy cameras with filter wheels.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I attach a 2-inch filter to the Askar 120APO Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe flattener comes with an M48 adapter that has internal M48x0.75 threads. You can screw a standard 2-inch mounted filter directly into this adapter before attaching your camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this flattener with a full-frame camera on my Askar 120APO to image the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this flattener is designed to fully illuminate and correct the field for full-frame sensors. When paired with the Askar 120APO's 840mm focal length, it provides an ideal image scale for large targets like the Andromeda Galaxy (M31) or the North America Nebula (NGC 7000), ensuring sharp stars across the entire frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat adapters are included with the Askar 1x Flattener for the 120APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe flattener provides two connection options on the camera side: a native M54×0.75 thread and an included adapter to step down to a standard M48×0.75 male thread for connecting most imaging equipment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 0.75kg flattener affect the balance of my Askar 120APO setup?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a weight of 0.75kg, the flattener will add some weight to the back of the telescope. You will likely need to re-balance your 120APO on its mount, especially after adding a camera and other accessories, to ensure accurate tracking.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet (3-element)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMagnification\u003c\/td\u003e\n\u003ctd\u003e1x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescope\u003c\/td\u003e\n\u003ctd\u003eAskar 120APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length (with 120APO)\u003c\/td\u003e\n\u003ctd\u003e840mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio (with 120APO)\u003c\/td\u003e\n\u003ctd\u003ef\/7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from M48 thread base)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera-Side Threads\u003c\/td\u003e\n\u003ctd\u003eM54x0.75 \u0026amp; M48x0.75 (via adapter)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Threads\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 (2-inch) inside M48 adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.75 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":50391393960221,"sku":"ASK-ASKFL12010","price":306.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/image_46b46ed0-dfff-499d-855f-a8e38dbde457.png?v=1758732981"},{"product_id":"askar-0-8x-reducer-for-120apo","title":"Askar 0.8x Reducer for 120APO","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces Askar 120APO to a fast f\/5.6 focal ratio\u003c\/li\u003e\n\u003cli\u003eShortens focal length to 672mm for wider fields of view\u003c\/li\u003e\n\u003cli\u003eTriplet optical design provides field flattening\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus from the M48 thread\u003c\/li\u003e\n\u003cli\u003eFeatures M68, M54, and M48 connection threads\u003c\/li\u003e\n\u003cli\u003eInternal M48x0.75 thread for 2\" filters\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 0.8x Reducer for 120APO\u003c\/h2\u003e\n\u003cp\u003eThe Askar 0.8x Reducer for 120APO transforms the telescope into a faster f\/5.6 imaging system, shortening its focal length to 672mm for capturing wider fields of view. This dedicated triplet reducer also functions as a field flattener, delivering sharp stars across the frame while maintaining the industry-standard 55mm back focus from its M48 thread for seamless integration with your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eA Faster f\/5.6 Focal Ratio and 672mm Focal Length\u003c\/h3\u003e\n\u003cp\u003eBy reducing the native f\/7 focal ratio of the Askar 120APO to a faster f\/5.6, this accessory significantly cuts down required exposure times, allowing you to gather more signal in less time. The corresponding focal length of 672mm creates a wider true field of view, perfect for framing large deep-sky objects like the Andromeda Galaxy (M31) or sprawling emission nebulae like the North America Nebula (NGC 7000).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet Optics Correcting for a 55mm Back Focus\u003c\/h3\u003e\n\u003cp\u003eEngineered with a three-element triplet optical design, this unit does more than just reduce the focal length; it actively corrects for field curvature. This ensures stars remain tight and point-like from the center to the edge of your sensor. The reducer is designed to achieve this correction at a standard 55mm back focus distance from the base of the M48 male thread, simplifying camera and accessory spacing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eM48, M54, and M68 Threads for a 0.75kg Payload\u003c\/h3\u003e\n\u003cp\u003eThis reducer provides a versatile set of connection options to accommodate various imaging setups, including M68x1, M54x0.75, and a standard M48x0.75 male thread. An internal M48 thread is also included for direct mounting of 2-inch filters. At 0.75kg, the reducer has a solid, CNC-machined build that requires re-balancing your telescope to accommodate the added weight on the imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 0.8x reducer change the Askar 120APO's performance?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer makes the Askar 120APO optically \"faster,\" changing its focal ratio from f\/7 to \u003cstrong\u003ef\/5.6\u003c\/strong\u003e. This reduces exposure times and provides a wider field of view by shortening the focal length to \u003cstrong\u003e672mm\u003c\/strong\u003e. It also functions as a field flattener, correcting for optical aberrations to keep stars sharp across the image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the correct back focus for the Askar 120APO 0.8x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe required back focus is a standard \u003cstrong\u003e55mm\u003c\/strong\u003e. This distance is measured from the base of the male M48x0.75 thread to your camera's sensor. This spacing is common for DSLR cameras with a T-ring or for dedicated astronomy cameras when combined with filter wheels and off-axis guiders.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar 120APO 0.8x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer features a built-in female \u003cstrong\u003eM48x0.75 thread\u003c\/strong\u003e on the telescope side of the M48 adapter, which is designed to accept standard 2-inch astronomy filters. This allows you to thread filters directly into the optical train for light pollution suppression or narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar 0.8x Reducer just a reducer or also a flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is both. While its primary function is to reduce the focal length, the \u003cstrong\u003etriplet optical design\u003c\/strong\u003e is engineered to correct for field curvature, an aberration common in refractor telescopes. This ensures that stars are sharp not only in the center of your image but also at the corners.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this reducer allow me to image the entire Andromeda Galaxy (M31) with the Askar 120APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, for most camera sensors. The reduced focal length of \u003cstrong\u003e672mm\u003c\/strong\u003e provides a much wider field of view than the native telescope. This makes it ideal for capturing large targets like the Andromeda Galaxy (M31) or the Heart and Soul Nebulae (IC 1805 and IC 1848) within a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIf I'm imaging the Pleiades (M45) with the Askar 120APO, what's the main benefit of using this 0.8x reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe main benefit is framing. The Pleiades (M45) is a large open star cluster, and at the native focal length of the 120APO, it can be difficult to fit the entire cluster and its surrounding nebulosity in the frame. The \u003cstrong\u003e672mm\u003c\/strong\u003e reduced focal length provides the wide field necessary to capture the cluster in its entirety, while the faster \u003cstrong\u003ef\/5.6\u003c\/strong\u003e optics will better capture the faint, blue reflection nebulosity with shorter exposures.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd\u003eAskar 120APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Length\u003c\/td\u003e\n\u003ctd\u003e672mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnection Threads\u003c\/td\u003e\n\u003ctd\u003eM68x1, M54x0.75, M48x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 (Internal, for 2\" filters)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.75 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 0.8x Reducer for 120APO\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_120APO_0.8x_Reducer_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":50391397204253,"sku":"ASK-ASKRE12008","price":306.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/image_a31c9216-816d-44c9-bf49-9aaa6f3eaaa9.png?v=1758733646"},{"product_id":"askar-111f","title":"Askar 111F 0.74× Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces Telescope Focal Ratio to f\/5.1\u003c\/li\u003e\n\u003cli\u003eCreates a 566mm Focal Length Imaging System\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design for Field Flattening\u003c\/li\u003e\n\u003cli\u003eProvides Standard 55mm Back Focus\u003c\/li\u003e\n\u003cli\u003eWeighs 0.5kg\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 111F 0.74× Reducer\u003c\/h2\u003e\n\u003cp\u003eThe Askar 111F 0.74× Reducer converts the telescope into a fast f\/5.1 astrograph, shortening the focal length to 566mm for wider fields of view. This triplet reducer establishes a standard 55mm back focus from its M48 male thread and weighs just 0.5kg, ensuring compatibility with a wide range of modern imaging cameras and accessories.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003ef\/5.1 Speed: A 0.74x Reduction for Wider Fields\u003c\/h3\u003e\n\u003cp\u003eBy reducing the focal ratio to f\/5.1, this accessory significantly cuts down the required exposure time for faint deep-sky objects. The corresponding 566mm focal length widens the field of view, allowing you to frame large targets like the Andromeda Galaxy (M31) or the North America Nebula (NGC 7000) in their entirety on a full-frame sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eOptical Correction: A 3-Element Design for Flat Fields\u003c\/h3\u003e\n\u003cp\u003eThe internal triplet lens design corrects for field curvature, ensuring stars remain sharp and round from the center to the edge of the frame. This level of correction is critical for modern, large-format CMOS and CCD sensors, eliminating optical distortions that would otherwise elongate stars in the corners of your images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eMechanical Design: 55mm Back Focus and Integrated Filter Threads\u003c\/h3\u003e\n\u003cp\u003eEngineered for seamless integration, the reducer presents a standard 55mm back focus distance measured from the base of its M48 male camera connection. This simplifies the process of adding off-axis guiders or filter wheels into your imaging train. The reducer attaches to the telescope's focuser via an M68x1 thread, and the camera-side adapter includes threads for standard 2-inch (M48x0.75) filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main benefit of the Askar 111F 0.74x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary benefit is speed. By converting the Askar 111F to an \u003cstrong\u003ef\/5.1\u003c\/strong\u003e system with a \u003cstrong\u003e566mm\u003c\/strong\u003e focal length, it reduces exposure times by approximately 45% compared to the native focal ratio. This allows you to capture more data on faint objects in less time while also providing a wider field of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I achieve the correct 55mm spacing for the 111F 0.74x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e55mm back focus\u003c\/strong\u003e is measured from the base of the M48 male thread on the reducer to your camera's sensor. Most dedicated astronomy cameras and DSLR\/mirrorless camera T-rings are designed to this 55mm standard, so in many cases, you can connect your camera directly. If you add a filter wheel or off-axis guider, you must use extension rings to ensure the total distance remains exactly 55mm.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use filters with the Askar 111F 0.74x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer features a built-in M48x0.75 thread on the camera side, which allows you to directly attach standard \u003cstrong\u003e2-inch astronomical filters\u003c\/strong\u003e. This is ideal for using light pollution, narrowband, or LRGB filters without needing a separate filter drawer or wheel for simple setups.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the 111F 0.74x Reducer change my image of the Andromeda Galaxy (M31) with the Askar 111F?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe native focal length of the Askar 111F is too long to fit the entire Andromeda Galaxy (M31) and its satellite galaxies on a full-frame sensor. By shortening the focal length to \u003cstrong\u003e566mm\u003c\/strong\u003e, the 0.74x Reducer provides a field of view wide enough to capture the full expanse of the galaxy in a single frame, making it an essential accessory for imaging large celestial targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the 111F 0.74x Reducer work with my full-frame camera on the Askar 111F?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the \u003cstrong\u003etriplet\u003c\/strong\u003e optical design is corrected for a large image circle sufficient for full-frame sensors. It effectively flattens the field to ensure that stars in the corners of a full-frame image remain sharp and are not affected by coma or field curvature.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar 111F 0.74x Reducer compatible with other telescopes?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this reducer is an optically matched accessory designed specifically for the Askar 111F APO Triplet Refractor. Using it with other telescopes will likely result in poor optical correction and an inability to reach focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Length\u003c\/td\u003e\n\u003ctd\u003e566mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Connection Thread\u003c\/td\u003e\n\u003ctd\u003eM68x1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.5 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_111F_Flat-Field_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":52851331006749,"sku":"ASK-ASAPO111R","price":419.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-111F-0-74-Reducer-1_ab87a539-90f5-488c-aeaf-5554073315a8.jpg?v=1788401687"},{"product_id":"askar-1x-flattener-for-185apo","title":"Askar 185APO 1x Full-frame Flattener","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eMaintains Native f\/7 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eMaintains Native 1295mm Focal Length\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus\u003c\/li\u003e\n\u003cli\u003eIncludes M68, M54 \u0026amp; M48 Adapters\u003c\/li\u003e\n\u003cli\u003eWeight: 0.74kg\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 185APO 1x Full-frame Flattener\u003c\/h2\u003e\n\u003cp\u003eThe Askar 185APO 1x Full-frame Flattener is a dedicated triplet corrector that maintains the telescope's native 1295mm focal length and f\/7 focal ratio for maximum image scale. It establishes a standard 55mm back focus from its M48 male thread and includes M68 and M54 adapters for versatile camera connection, all within a 0.74kg assembly.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet Optics: Full-Frame Correction at a Native f\/7\u003c\/h3\u003e\n\u003cp\u003eDesigned specifically for the Askar 185APO, this flattener uses a three-element optical layout to eliminate field curvature and coma across a full-frame sensor. By preserving the telescope's native f\/7 focal ratio, you can capture deep-sky objects with the highest possible resolution, ensuring that stars remain sharp and pinpoint from the center of the frame to the corners.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Back Focus with M68, M54, and M48 Adapters\u003c\/h3\u003e\n\u003cp\u003eThis flattener simplifies your imaging train by adhering to the industry-standard 55mm back focus distance. This spacing is ideal for use with DSLRs, mirrorless cameras, and dedicated astronomy cameras connected to a filter wheel. The unit includes M68×1, M54×0.75, and M48×0.75 adapters, providing robust, threaded connections for a wide range of equipment. A built-in M48×0.75 thread also allows for the direct installation of 2-inch filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e1x Flattener vs. 0.8x Reducer: Imaging at the Native 1295mm Focal Length\u003c\/h3\u003e\n\u003cp\u003eChoosing between this 1x flattener and the optional 0.8x reducer depends entirely on your target. The 1x flattener is the superior choice when image scale is the priority, allowing you to resolve fine details in smaller targets like the Whirlpool Galaxy (M51) or the Ring Nebula (M57) at the full 1295mm focal length. The reducer, in contrast, provides a wider field of view and a faster f\/5.6 focal ratio, better suited for capturing large nebulae like the North American Nebula (NGC 7000) in a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the Askar 185APO 1x Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary purpose of the Askar 185APO 1x Flattener is to correct for optical aberrations inherent in refractor telescopes, specifically \u003cstrong\u003efield curvature\u003c\/strong\u003e. It ensures that stars are sharp and round across the entire imaging sensor, especially larger full-frame sensors, without changing the telescope's native \u003cstrong\u003e1295mm focal length\u003c\/strong\u003e or \u003cstrong\u003ef\/7 focal ratio\u003c\/strong\u003e.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I achieve the correct 55mm back focus with the 185APO 1x Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e55mm back focus\u003c\/strong\u003e is measured from the base of the M48 male thread on the included adapter to your camera's sensor. Most dedicated astronomy cameras, when paired with a filter wheel and off-axis guider, are designed to meet this 55mm standard. For DSLR or mirrorless cameras, a standard 48mm T-ring is typically all that is needed to achieve the correct spacing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar 185APO 1x Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The flattener's M54-to-M48 adapter has an internal \u003cstrong\u003eM48×0.75 filter thread\u003c\/strong\u003e. This allows you to screw a standard 2-inch astronomy filter directly into the imaging train before it connects to your camera.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 1x flattener work with telescopes other than the Askar 185APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this flattener is optically matched specifically for the Askar 185APO refractor. Using it with other telescopes will likely result in poor optical correction and may not reach focus. For best results, always use the dedicated flattener designed for your specific telescope model.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 185APO 1x Flattener or the 0.8x reducer better for imaging the Whirlpool Galaxy (M51)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor a relatively small target like the Whirlpool Galaxy (M51), the \u003cstrong\u003e1x flattener\u003c\/strong\u003e is the ideal choice. It preserves the telescope's native \u003cstrong\u003e1295mm focal length\u003c\/strong\u003e, providing the maximum image scale to resolve details like spiral arms and dust lanes. The 0.8x reducer would shrink the galaxy on the sensor, making it less detailed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat camera combination works with the 55mm back focus of the 185APO 1x Flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA standard setup for the \u003cstrong\u003e55mm back focus\u003c\/strong\u003e would be a dedicated astronomy camera (e.g., ZWO or QHY) with a sensor-to-flange distance of 17.5mm, connected to a 21mm filter wheel and a 16.5mm off-axis guider. This combination totals exactly 55mm. Alternatively, a DSLR with a standard T-ring also meets the 55mm requirement.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length (with 185APO)\u003c\/td\u003e\n\u003ctd\u003e1295mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio (with 185APO)\u003c\/td\u003e\n\u003ctd\u003ef\/7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.74kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear-end Threads\u003c\/td\u003e\n\u003ctd\u003eM68×1, M54×0.75, M48×0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eM48×0.75 (inside M48 adapter)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_185APO_1x_Flattener_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e185APO 1x Full-frame Flattener\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eFront Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eRear Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_185APO_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":52851334971677,"sku":"ASK-ASKFL18510","price":460.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-185APO-1x-Full-frame-Flattener-1_f8658ff2-b22c-4344-927f-2ace2e320c21.jpg?v=1788401737"},{"product_id":"askar-0-8x-reducer-for-185apo","title":"Askar 185APO 0.8x Full-frame Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces Askar 185APO to f\/5.6\u003c\/li\u003e\n\u003cli\u003eResulting Focal Length: 1036mm\u003c\/li\u003e\n\u003cli\u003e4-Element Quadruplet Optical Design\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus\u003c\/li\u003e\n\u003cli\u003eIlluminates Full-Frame Sensors\u003c\/li\u003e\n\u003cli\u003eWeight: 0.95kg\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 185APO 0.8x Full-frame Reducer\u003c\/h2\u003e\n\u003cp\u003eThe Askar 185APO 0.8x Full-frame Reducer transforms its dedicated telescope into a faster, wider imaging system, shortening the native focal ratio to f\/5.6 and the focal length to 1036mm. Its 4-element quadruplet design corrects for field curvature across a full-frame sensor, while the standard 55mm back focus ensures compatibility with a wide range of cameras and accessories. Weighing just 0.95kg, it provides multiple rear-end threads including M68×1, M54×0.75, and M48×0.75 for direct integration into your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eQuadruplet Optics: Reducing the 185APO to a Fast f\/5.6\u003c\/h3\u003e\n\u003cp\u003eThis reducer is engineered specifically for the Askar 185APO, converting it to a faster f\/5.6 instrument. This reduction in focal ratio significantly cuts required exposure times and expands the field of view, making it ideal for capturing vast emission nebulae like the North American Nebula (NGC 7000) or sprawling star clusters in a single frame. The 4-element quadruplet optical design acts as a field flattener, ensuring stars remain sharp and pinpoint across the entire full-frame image circle without introducing optical aberrations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e55mm Back Focus and Flexible Full-Frame Connections\u003c\/h3\u003e\n\u003cp\u003eIntegration with your existing gear is straightforward. The reducer provides a standard 55mm back focus distance measured from the base of its M48 male thread, matching the requirement for DSLRs with a T-ring and many cooled astronomy cameras when used with a filter wheel. For maximum flexibility, the reducer includes M68×1, M54×0.75, and M48×0.75 adapters on the camera side. It also features an internal M48×0.75 thread, allowing you to mount standard 2-inch filters directly inside the reducer body, simplifying your optical train and maintaining correct spacing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main benefit of using the 0.8x reducer with the Askar 185APO?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary benefit is speed. By reducing the focal ratio to f\/5.6, you can gather the same amount of light in a significantly shorter time compared to the telescope's native f\/7. This allows for higher quality images with less total exposure time and reduces demands on your mount's tracking accuracy. It also provides a wider field of view for imaging large celestial objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the Askar 185APO 0.8x Reducer achieve a flat field?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer uses a \u003cstrong\u003e4-element quadruplet optical design\u003c\/strong\u003e. This sophisticated lens arrangement is engineered not only to reduce the focal length but also to correct for off-axis aberrations like field curvature and coma, which are common in fast optical systems. This ensures that stars are sharp and round from the center of the image to the corners of a full-frame sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 55mm back focus on the 185APO reducer compatible with my DSLR?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The standard 55mm back focus is the industry standard for DSLR and mirrorless cameras when using a typical T-ring adapter. You can attach your camera directly to the reducer's M48 thread with the appropriate T-ring for your camera model and achieve perfect spacing without extra calculations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the Askar 185APO 0.8x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer features a built-in M48×0.75 female thread on the camera side, which is the standard for 2-inch astronomy filters. You can thread your filters directly into the reducer itself, placing them at an optimal position within the light path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the 185APO 0.8x Reducer change my framing for a large target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith the reducer, the 185APO operates at a 1036mm focal length. This wider field of view is much better suited for capturing the full extent of massive objects like the Andromeda Galaxy (M31) or the Veil Nebula complex on a full-frame sensor. Without the reducer, you would likely need to create a multi-panel mosaic to capture these targets in their entirety.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI have a cooled camera with a 20mm filter wheel. How do I achieve the 55mm back focus with the 185APO reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 55mm back focus is measured from the M48 thread flange on the reducer. You'll need to account for the light path consumed by your equipment. If your camera sensor's back focus is 17.5mm and your filter wheel is 20mm thick, you have used 37.5mm of the available 55mm. You would need 17.5mm of M48 extension tubes between the reducer and your filter wheel to achieve the correct spacing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length (with 185APO)\u003c\/td\u003e\n\u003ctd\u003e1036mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio (with 185APO)\u003c\/td\u003e\n\u003ctd\u003ef\/5.6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eQuadruplet (4-Element)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.95kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear-end Connection Threads\u003c\/td\u003e\n\u003ctd\u003eM68×1, M54×0.75, M48×0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInternal Filter Thread\u003c\/td\u003e\n\u003ctd\u003eM48×0.75 (2-inch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_185APO_0.8x_Reducer_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e185APO 0.8x Full-frame Reducer\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eFront Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eRear Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar_2025_First_Half_Product_Collection_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":52851335201053,"sku":"ASK-ASKRE18508","price":460.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-185APO-0-8x-Full-frame-Reducer-1_fc1d732e-256e-44e9-b8a9-6b75ba94c728.jpg?v=1788401745"},{"product_id":"askar-0-75x-reducer-for-60f","title":"Askar 60F 0.75x Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e0.75x Focal Reduction\u003c\/li\u003e\n\u003cli\u003eReduces Focal Length to 311mm\u003c\/li\u003e\n\u003cli\u003eCreates a Fast f\/5.1 Focal Ratio\u003c\/li\u003e\n\u003cli\u003e44mm Full-Frame Image Circle\u003c\/li\u003e\n\u003cli\u003eStandard 55mm Back Focus\u003c\/li\u003e\n\u003cli\u003eTriplet Optical Design\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 60F 0.75x Reducer\u003c\/h2\u003e\n\u003cp\u003eDesigned exclusively for the Askar 60F refractor, this 0.75x Reducer transforms the telescope into a faster, wider imaging system, shortening the focal length to 311mm and the focal ratio to a swift f\/5.1. The three-element triplet optical design simultaneously flattens the field, delivering a corrected 44mm image circle that fully illuminates full-frame sensors with a standard 55mm back focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e0.75x Reduction: Transform Your 60F to a Fast f\/5.1 Astrograph\u003c\/h3\u003e\n\u003cp\u003eBy converting your Askar 60F to an f\/5.1 instrument, this reducer significantly cuts down required exposure times, allowing you to gather more signal in less time. This speed is critical for capturing faint details in nebulae or for imaging transient objects. The wider field of view produced by the 311mm focal length makes it possible to frame large targets like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000) in their entirety.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet Optics: A Flat 44mm Image Circle for Full-Frame Sensors\u003c\/h3\u003e\n\u003cp\u003eThe reducer employs a three-element, air-spaced triplet lens configuration that acts as a field flattener, correcting for the optical aberrations inherent in a curved focal plane. This results in a 44mm image circle, large enough to cover modern full-frame CMOS and CCD sensors without vignetting. You will see sharp, point-like stars across the entire frame, from the center to the very corners of your images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSeamless Integration: 55mm Back Focus and Built-in Filter Cell\u003c\/h3\u003e\n\u003cp\u003eEngineered for convenience, the reducer features a standard 55mm back focus from its M48 male threads, simplifying the process of connecting DSLRs, mirrorless cameras, or dedicated astronomy cameras with standard spacers. A key feature is the integrated M48x0.75 thread at the front of the adapter, which allows you to directly attach 2-inch filters. This eliminates the need for a separate filter drawer or wheel in your imaging train, saving precious back focus and reducing complexity.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main benefit of using the 60F 0.75x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary benefits are speed and field of view. The reducer converts the Askar 60F to a faster \u003cstrong\u003ef\/5.1\u003c\/strong\u003e optical system, which dramatically shortens exposure times. It also widens the field of view by reducing the focal length to \u003cstrong\u003e311mm\u003c\/strong\u003e, allowing you to capture larger celestial objects in a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 0.75x reducer work with telescopes other than the Askar 60F?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. This reducer is optically designed and threaded specifically for the Askar 60F refractor. Using it with other telescopes will result in poor optical performance and an inability to reach focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the 60F 0.75x Reducer support full-frame cameras?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. It is designed to produce a flat, fully-illuminated \u003cstrong\u003e44mm image circle\u003c\/strong\u003e, which is large enough to cover the sensors of full-frame DSLR, mirrorless, and dedicated astronomy cameras without significant vignetting.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I install a 2-inch filter with this 60F reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer's adapter has a built-in \u003cstrong\u003eM48x0.75 thread\u003c\/strong\u003e at the front. You can simply screw any standard 2-inch astronomy filter directly into this thread, placing it securely in the optical path without needing a separate filter holder.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 60F 0.75x Reducer help when imaging a large target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eBy reducing the focal length to \u003cstrong\u003e311mm\u003c\/strong\u003e, the reducer provides a much wider field of view than the native telescope. This allows you to frame the entirety of the Andromeda Galaxy (M31) and its satellite galaxies M32 and M110 in a single shot. The faster \u003cstrong\u003ef\/5.1\u003c\/strong\u003e focal ratio also helps capture the faint outer arms of the galaxy more efficiently.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 55mm back focus of the Askar 60F Reducer difficult to achieve?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, \u003cstrong\u003e55mm\u003c\/strong\u003e is the industry standard for back focus. Most DSLR and mirrorless cameras with a standard 10mm T-ring achieve this distance perfectly. For dedicated astronomy cameras, achieving 55mm is straightforward using a combination of standard M48 extension tubes that are readily available.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.75x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Length\u003c\/td\u003e\n\u003ctd\u003e311mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from M48 male thread base)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear-end Thread\u003c\/td\u003e\n\u003ctd\u003eM50x1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.2kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAskar 60F 0.75x Reducer\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eFront Metal Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eRear Metal Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":52851335430429,"sku":"ASK-ASKAR60R","price":279.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-60F-0-75x-Reducer-1_c52c17eb-7904-4f98-9eee-8d2f4173fd83.jpg?v=1788401754"},{"product_id":"askar-0-75x-reducer-for-91f","title":"Askar 91F 0.75x Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces focal ratio to a fast f\/5\u003c\/li\u003e\n\u003cli\u003e0.75x reduction factor for wider fields of view\u003c\/li\u003e\n\u003cli\u003eTriplet optical design provides field-flattening correction\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus from the M48 thread\u003c\/li\u003e\n\u003cli\u003eLightweight 0.3kg construction\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 91F 0.75x Reducer\u003c\/h2\u003e\n\u003cp\u003eThe Askar 91F 0.75x Reducer transforms its dedicated telescope into a faster, wider imaging system, shortening the native focal length to 455mm and the focal ratio to a rapid f\/5. This triplet reducer is engineered to provide full-frame, field-flattened correction while maintaining a standard 55mm back focus for seamless integration with your existing M48-threaded imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eFaster f\/5 Imaging: The 0.75x Optical Advantage\u003c\/h3\u003e\n\u003cp\u003eBy decreasing the focal ratio to f\/5, this 0.75x reducer significantly cuts down required exposure times, allowing you to gather more signal on faint targets in less time. The wider field of view is ideal for capturing large-scale celestial objects that would otherwise be too expansive for the telescope's native field, such as the Andromeda Galaxy (M31) or the entire Veil Nebula complex.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eTriplet Design with 55mm Back Focus for Full-Frame Sensors\u003c\/h3\u003e\n\u003cp\u003eThe air-spaced triplet optical design not only reduces the focal length but also acts as a dedicated field flattener, ensuring sharp, point-like stars across a full-frame sensor. It establishes a standard 55mm back focus distance from its M48 male thread, simplifying the connection to DSLRs, mirrorless cameras, and dedicated astronomy cameras with common spacers.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Filter Thread:\u003c\/strong\u003e A built-in M48x0.75 thread allows you to mount 2-inch filters directly into the reducer, placing them securely within the optical path without needing a separate filter drawer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSecure Connection:\u003c\/strong\u003e The reducer attaches to the Askar 91F focuser via a robust M59*1 thread, ensuring a rigid, tilt-free connection for imaging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCNC Machining:\u003c\/strong\u003e The entire housing is CNC-machined for precision and durability, and includes threaded metal dust caps for protection when not in use.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eImaging with the Askar 91F: Native vs. f\/5 Reduced\u003c\/h3\u003e\n\u003cp\u003eThis reducer offers a critical choice for astrophotographers. Using the Askar 91F at its native focal length provides higher magnification, perfect for framing smaller galaxies or planetary nebulae where image scale is paramount. Attaching the 0.75x reducer is the superior option for large emission nebulae and star clusters, where its light-gathering speed and wider perspective are essential for capturing the entire object in a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the 91F 0.75x Reducer do for my Askar 91F telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 91F 0.75x Reducer shortens your telescope's focal ratio to a faster f\/5 and focal length to 455mm. This provides two main benefits: a \u003cstrong\u003ewider field of view\u003c\/strong\u003e to fit larger objects in the frame, and \u003cstrong\u003eshorter exposure times\u003c\/strong\u003e to capture faint details more efficiently.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I connect the Askar 91F 0.75x Reducer to my camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer provides a standard \u003cstrong\u003e55mm back focus\u003c\/strong\u003e from the base of its M48 male thread. This is a common standard for most astronomy cameras and DSLRs with the appropriate T-ring. You simply add or remove M48 spacers until the distance from the reducer's flange to your camera sensor is exactly 55mm.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch filters with the 91F 0.75x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The reducer has a built-in M48x0.75 female thread on the camera side, allowing you to directly screw in standard 2-inch astronomy filters. This is convenient for using light pollution or narrowband filters without needing a separate filter wheel or drawer.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar 91F 0.75x Reducer also a field flattener?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it is. The triplet optical design is engineered to provide field-flattening correction specifically for the Askar 91F telescope. This ensures that stars remain sharp and round across the entire image, even at the edges of a full-frame sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhich targets benefit most from the 91F 0.75x Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis reducer is ideal for large deep-sky objects that require a wide field of view. Excellent targets include the \u003cstrong\u003eNorth American Nebula (NGC 7000)\u003c\/strong\u003e, the \u003cstrong\u003eAndromeda Galaxy (M31)\u003c\/strong\u003e, and large star-forming regions like the Heart and Soul Nebulae (IC 1805 and IC 1848).\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhen should I *not* use the 91F 0.75x Reducer with my Askar 91F?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou should image without the reducer when your target is small and requires maximum image scale. For example, most galaxies like the Whirlpool Galaxy (M51), smaller planetary nebulae like the Ring Nebula (M57), or any planetary imaging would be better suited to the telescope's native, longer focal length.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.75x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting Focal Length\u003c\/td\u003e\n\u003ctd\u003e455mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResulting Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eTriplet, Air-Spaced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from M48 thread base)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Side Thread\u003c\/td\u003e\n\u003ctd\u003eM59*1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Side Thread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 (Male)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Thread\u003c\/td\u003e\n\u003ctd\u003eM48x0.75 (Female, for 2\" filters)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.3kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":52851336904989,"sku":"ASK-ASKAR91R","price":279.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-91F-0-75x-Reducer-1_234100f2-15d6-4254-a83f-7aaf11c45959.jpg?v=1788401763"},{"product_id":"askar-0-74x-reducer-for-131f","title":"Askar 131F 0.74× Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces telescope focal ratio to f\/5.6\u003c\/li\u003e\n\u003cli\u003eAchieves a 733.6mm final focal length\u003c\/li\u003e\n\u003cli\u003eTriplet optical design for field flattening\u003c\/li\u003e\n\u003cli\u003eStandard 55mm back focus from the M48 thread\u003c\/li\u003e\n\u003cli\u003eWeighs 0.56kg\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eAskar 131F 0.74× Reducer\u003c\/h2\u003e\n\u003cp\u003eThe Askar 131F 0.74x Reducer converts the Askar 131F refractor into a faster f\/5.6 astrograph with a final focal length of 733.6mm. This dedicated triplet reducer provides a wider field of view and significantly shortens exposure times, all while maintaining a precise 55mm back focus distance and weighing just 0.56kg.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e0.74x Reduction: Transforming the 131F to an f\/5.6 Astrograph\u003c\/h3\u003e\n\u003cp\u003eBy reducing the native f\/7.5 optics of the Askar 131F to a faster f\/5.6, this reducer cuts required exposure times by nearly half. This speed is critical for capturing faint details in nebulae and galaxies. The triplet optical design doesn't just reduce the focal length to 733.6mm; it also flattens the field, ensuring stars remain sharp and round across a full-frame sensor from the center to the corners of your image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eMechanical Design: 55mm Back Focus and Full-Frame Correction\u003c\/h3\u003e\n\u003cp\u003eEngineered for seamless integration, the reducer maintains the industry-standard 55mm back focus distance, measured from the base of its M48 male thread. This simplifies the process of connecting your DSLR, mirrorless, or dedicated astronomy camera with standard adapters and off-axis guiders. The main body features a rear-end M72x1 thread for a secure connection to the telescope's focuser, and the CNC-machined housing ensures precise optical alignment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the Askar 131F 0.74× Reducer do to my telescope's focal length?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 0.74x Reducer shortens the Askar 131F's native focal length to \u003cstrong\u003e733.6mm\u003c\/strong\u003e and speeds up the focal ratio from f\/7.5 to \u003cstrong\u003ef\/5.6\u003c\/strong\u003e. This provides a wider field of view and gathers light more quickly, reducing your total imaging time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the back focus of the Askar 131F 0.74× Reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe required back focus is \u003cstrong\u003e55mm\u003c\/strong\u003e, measured from the base of the male M48 thread on the reducer. This is a standard distance that works directly with most DSLR cameras using a T-ring and many dedicated astronomy camera setups.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Askar 131F 0.74× Reducer help me image the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Andromeda Galaxy is a very large target. The reducer's \u003cstrong\u003e733.6mm\u003c\/strong\u003e focal length provides a wider field of view, allowing you to capture the entire galaxy and its faint outer arms within a single frame using a full-frame or APS-C sensor. The faster \u003cstrong\u003ef\/5.6\u003c\/strong\u003e optics will also help you capture more signal in less time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Askar 131F 0.74× Reducer suitable for imaging large nebulae like the North American Nebula (NGC 7000)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The wide field of view provided by the \u003cstrong\u003e733.6mm\u003c\/strong\u003e focal length is ideal for framing large emission nebulae like NGC 7000. Furthermore, the fast \u003cstrong\u003ef\/5.6\u003c\/strong\u003e focal ratio is highly effective at capturing faint hydrogen-alpha signal, making it a perfect match for such targets.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of optical correction does the Askar 131F 0.74× Reducer provide?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer uses a \u003cstrong\u003etriplet lens design\u003c\/strong\u003e. This multi-element configuration is engineered not only to reduce the focal length but also to act as a field flattener, correcting for the natural field curvature of the main optics. This ensures that stars are sharp across the entire imaging sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow much does the Askar 131F 0.74× Reducer weigh?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe reducer weighs \u003cstrong\u003e0.56kg\u003c\/strong\u003e. This is an important consideration for ensuring your mount remains properly balanced after adding the reducer and camera to the optical train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduction Factor\u003c\/td\u003e\n\u003ctd\u003e0.74x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Length\u003c\/td\u003e\n\u003ctd\u003e733.6mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReduced Focal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Design\u003c\/td\u003e\n\u003ctd\u003eTriplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (from the base of M48 male thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.56kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear-end Thread\u003c\/td\u003e\n\u003ctd\u003eM72x1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Askar","offers":[{"title":"Default Title","offer_id":52851337429277,"sku":"ASK-ASKAR131FRD","price":419.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-131F-0-74-Reducer-1_efb7cdda-5cf2-46a8-a24c-8bb2c26ac7dd.jpg?v=1788401779"}],"url":"https:\/\/davidastro.com\/en-us\/collections\/askar-field-flatteners-reducers-and-coma-correctors.oembed","provider":"David Astro","version":"1.0","type":"link"}