Askar 130PHQ f/7.7 Quadruplet

130PHQ is a long-focal-ratio, flatfield astrograph newly launched after 107PHQ. Instead of buying extra flatteners, calculating the backfocus of flattener or making tedious connection to match the distance, astrophotographers can simply equip it with any possible imaging devices, make the target stay at the focus, and then the whole optical system is perfect for imaging. 130PHQ has a larger size than 107PHQ, with an aperture 23mm larger than 107PHQ. 130PHQ has a focal ratio of f/7.7 which is longer than 107PHQ’ s f/7, and a focal length of 1000mm. The quadruplet lens with two ED glasses offers excellent control of chromatic and other aberrations. With its self-flattening design, 130PHQ offers strong advantages in astronomical shooting. It supports a medium frame 60mm image circle, has a fine spot diagram with tiny distortion of the peripheral stars, and its central RMS radius is less than 2 microns.