Askar FRA 400 72mm f/5.6 Quintuplet Flat-Field Astrograph

Product introduction Welcome to our brand new Askar FRA series! The FRA, which stands for “Flat-field Refractive Astrograph”,is a refractive equipment with built-in flat field correction. FRA can also be applied in visual observation. So the FRA series is among the few versatile and quality astrophotographic devices in the current astronomy market. For easy parameter conversion between different lenses, the first-come of the FRA family features a Petzval-like quintuplet design (two pieces of which are special ED glass) with an aperture of 72mm, a focal length of 400mm and a focal ratio of f/5.6, providing a 44mm image circle. The FRA400 quintuplet astrograph has adopted modern optical design with a retractable dew shield, a 3" rack-and-gear-based high-precision reducer containing a 360-degree rotator, M68×1 thread, a 2" adapter ring and a 1.25" visual adapter. Th