◇ FRA500 has a focal ratio of f/5.6 and a focal length of 500mm.
◇ From the front, the Askar FRA500 has an impressive dew shield decorated with a classic bright-red bezel ring. The OTA weighs 4.1kg, and the full package with tube rings, etc. weighs 5.2kg.
◇ On the top of the tube rings attached a handle and at the bottom, there is an Askar Losmandy-style dovetail plate. The combination of milk-white main tube and dew shield together with a high-gloss piano-black focuser makes the optical tube assembly calm and deep which is offset by the bright red decorative ring and tube rings.
550mm focal length
Sextuplet air- spaced APO design
Retractable lens hood
500mm focal length
300mm dovetail plate
◇ It boasts a quintuplet air-spaced APO optical structure, a “three plus two” Petzval lens combination. The front lens group consists of three lenses (including two pieces of ED glass) for excellent correction of aberrations.
◇ With its self-flattening design, FRA500 offers strong advantages in the astronomical shooting.
◇ FRA500 supports an image circle of amazing 55mm, much larger than the standard 44mm full-frame image circle.
Quintuplet air- spaced APO design
Supporting full frame
0.7x Reducer (optional)
◇ At the tail end of the astrograph locates a 3.5" massively-built focuser with dual-speed hand knobs (twin knobs for coarse adjustment and one 1:10 fine adjustment knob), which is of great use in real observation or astrophotography.
◇ The astrograph wears smooth coating and is evenly finished. The graduation inside of the focuser is quite clear and easily readable. The focuser is tough and solid, and on the left side of it, there is a standard finder base with a silver thumb screw. So the FRA500 can piggyback carry finders, guiders or other potential astronomy accessories.
No need for flattener
No need to calculate the backfocus
3.5" large rack-pinion focuser
1:10 fine adjustment