Askar 71F 70mm f/6.9 Quadruplet Flat-Field Astrograph Telescope

Product introduction   71mm aperture 490mm focal length Quadruplet APO design 1 piece ED glass Supporting full frame No need for flattener No need to calculate the backfocus Retractable lens hood 360° rotator 2 Finder bases 2.4 inch R&P focuser 1:10 fine adjustment 1.25'' visual adapter 230mm Vixen dovetail plate 4-piece photographic adapters 1.25-inch 45° erecting prism 8mm eyepiece 20mm eyepiece   The Askar 71F is an OTA with an aperture of 71mm, a focal length of 490mm, and a native focal ratio of F6.9. The Askar 71F adopts a quadruplet air-spaced APO lens design, including one piece of ED glass， which can effectively reduce chromatic aberration. The Askar 71F supports 44mm full-frame imaging with great performance of the surrounding star points. The Askar 71F is a self-flattened design that allows users to avoid calculating the back focus and buying additional flattener, after attaching the imaging accessories, users can directly us