{"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":199.0,"currency_code":"USD","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","url":"https:\/\/davidastro.com\/en-eu\/products\/askar-0-75x-reducer-for-60f","provider":"David Astro","version":"1.0","type":"link"}