{"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":221.16,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/image_a31c9216-816d-44c9-bf49-9aaa6f3eaaa9.png?v=1758733646","url":"https:\/\/davidastro.com\/fr-us\/products\/askar-0-8x-reducer-for-120apo","provider":"David Astro","version":"1.0","type":"link"}