{"product_id":"explore-scientific-es-fr0-8x","title":"Explore Scientific 0.8x Focal Reducer","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eReduces focal length by a factor of 0.8x for wider fields of view\u003c\/li\u003e\n\u003cli\u003eEngineered for refractors with focal ratios from f\/5 to f\/7\u003c\/li\u003e\n\u003cli\u003eProvides 55mm (+\/- 2mm) of back focus for correct spacing\u003c\/li\u003e\n\u003cli\u003eFeatures standard M42x0.75 T-threads for easy camera attachment\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\u003eExplore Scientific 0.8x Focal Reducer\u003c\/h2\u003e\n\u003cp\u003eThe Explore Scientific 0.8x Focal Reducer converts refractors in the f\/5 to f\/7 range into faster, wider-field astrographs, reducing your scope's effective focal ratio for significantly shorter exposures. This corrector provides a precise 55mm (+\/- 2mm) of back focus and connects to your camera using standard M42 T-threads, creating a simple and rigid imaging train for capturing large nebulae and star fields.\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, Wider Imaging: 0.8x Reduction for f\/5-f\/7 Refractors\u003c\/h3\u003e\n\u003cp\u003eBy reducing your telescope's focal length by a factor of 0.8x, this accessory broadens your field of view, allowing you to frame large targets like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000) in their entirety. More importantly, it makes your optical system faster, concentrating the same amount of light onto a smaller area of your camera's sensor. An f\/6 refractor becomes an f\/4.8 system, enabling you to capture the same level of detail in nearly 40% less time.\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\u003ePrecise Spacing for Sharp Stars: 55mm Back Focus and M42 Threads\u003c\/h3\u003e\n\u003cp\u003eAchieving a flat field with sharp stars to the edge requires precise spacing between the reducer and the camera sensor. This reducer is designed with a 55mm back focus distance, the industry standard for DSLR cameras connected via a T-ring, which simplifies setup. The body is threaded to accept any standard 42mm (M42x0.75) T-ring or T-threaded accessory, ensuring a secure, non-flexing connection to your imaging equipment.\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 Explore Scientific 0.8x Focal Reducer do to my telescope's focal ratio?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Explore Scientific 0.8x Focal Reducer multiplies your telescope's native focal ratio by 0.8. For example, if you have an f\/7 refractor, using this reducer will convert it into a faster f\/5.6 imaging system (7 x 0.8 = 5.6). This allows for shorter exposure times and 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 with the Explore Scientific 0.8x 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 the required distance from the shoulder of the reducer's threads to your camera's sensor. This is easily achieved with most cameras:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDSLR\/Mirrorless Cameras:\u003c\/strong\u003e A standard T-ring for your camera model is typically all that is needed, as the combination of the camera's flange distance and the T-ring height equals 55mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDedicated Astronomy Cameras:\u003c\/strong\u003e You will need to use a combination of M42 extension tubes to build up the distance from your camera's sensor to the reducer. Check your camera's documentation for its sensor depth to calculate the required extension length.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Explore Scientific 0.8x Reducer compatible with my f\/8 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis reducer is optically optimized for refractors in the \u003cstrong\u003ef\/5 to f\/7 range\u003c\/strong\u003e. While it may thread into an f\/8 or slower telescope, performance is not guaranteed. Using it outside the recommended range can lead to field curvature or other aberrations, particularly at the edges of the image.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Explore Scientific 0.8x Reducer work for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is an imaging-only accessory. Focal reducers are designed to project a corrected, flat image plane directly onto a camera sensor. They are not designed to work with eyepieces and will not reach focus for visual use.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will this 0.8x reducer help me image the Andromeda Galaxy (M31) with my 80mm f\/6 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn 80mm f\/6 refractor has a 480mm focal length. The Explore Scientific 0.8x Reducer will shorten this to 384mm (f\/4.8). This wider field of view is crucial for fitting the entire 3-degree span of the Andromeda Galaxy (M31) onto a camera with an APS-C or smaller sensor, which would be impossible at the native focal length.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this reducer to capture the full extent of the North American Nebula (NGC 7000) with a 102mm f\/7 refractor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. A 102mm f\/7 refractor has a 714mm focal length. The Explore Scientific 0.8x Reducer brings this down to about 571mm (f\/5.6). This reduction is essential for capturing the sprawling expanse of the North American Nebula (NGC 7000) and the adjacent Pelican Nebula (IC 5070) in a single frame, especially with popular APS-C sized sensors.\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\u003eRecommended Telescope F\/Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5 to f\/7 Refractors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e55mm (+\/- 2mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Connection Thread\u003c\/td\u003e\n\u003ctd\u003eM42 x 0.75 (T-Thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGTIN\u003c\/td\u003e\n\u003ctd\u003e811803035881\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\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/explore-scientific-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eExplore Scientific Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":52909419102493,"sku":"ES-FR0.8x","price":139.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/ExploreScientific-0-8x-Focal-Reducer-1_7405fa1d-974f-45d2-983b-5b5414514eff.jpg?v=1789061637","url":"https:\/\/davidastro.com\/fr-us\/products\/explore-scientific-es-fr0-8x","provider":"David Astro","version":"1.0","type":"link"}