Sharpstar Optics has announced the latest member of its FRA line, the FRA500 astrograph. With an aperture of 90mm and a 500mm focal length (f/5.6), this refractor fits in the middle of Sharpstar’s FRA line. The optical design is a quintuplet air-spaced Petzval APO system with a front lens group of three lenses (two of ED glass), and a rear group of two air-spaced lenses. The resulting image circle is 55mm in diameter. The 3.5″ focuser dual-speed focuser provides up to 158mm of back-focus, depending on the adapter used, and sports a standard finder base for finders, guiders, and other accessories. Tube rings with a handle for transport, a Losmandy-style dovetail plate, and a built-in, retractable lens hood are included.
MSRP: $1999
Website: www.askarlens.com
