Askar FRA500 The Askar FRA500 combines a 90 mm aperture, 500 mm focal length and f/5.6 focal ratio. Its quintuplet 3+2 Petzval system includes two ED elements and supports a 55 mm image circle, extending beyond a conventional full-frame sensor.
Manufacturer model: Askar FRA500 · Specifications checked against manufacturer data on 2026-11-04
The Askar FRA500 combines a 90 mm aperture, 500 mm focal length and f/5.6 focal ratio. Its quintuplet 3+2 Petzval system includes two ED elements and supports a 55 mm image circle, extending beyond a conventional full-frame sensor.
Native field correction is integrated. Fit the camera train within the published connection limits and focus; an additional native flattener is unnecessary. Askar specifies 85 mm from the M48×0.75 conical-extender reference or 158 mm from the M86×1 rotator reference to the focal plane.
A 3.5-inch rack-and-pinion focuser provides coarse and 1:10 fine adjustment. The telescope includes a finder base, tube rings, multifunction handle and a 300 mm Losmandy-style dovetail plate. The retractable hood reduces transport length.
The technical table lists 407 mm contracted and 452 mm extended, with 4.1 kg bare OTA and 5.2 kg including rings and dovetail. A matching f/3.9 reducer is separately available for a wider, faster configuration and has its own prescribed camera spacing.
Askar manufacturer documentation
Length follows the technical table: 452 mm extended, 407 mm contracted. Introductory text instead rounds the contracted length to 410 mm.
| Maximum accessory connection | 85mm（from base of M48×0.75 thread on the conical extender to focal plane） 158mm（from base of M86×1 thread on the rotator to focal plane） |
|---|---|
| Conical adapter threads | 48×0.75 |
| Finder base | Included |
Data sheet
Askar FRA500 The Askar FRA500 combines a 90 mm aperture, 500 mm focal length and f/5.6 focal ratio. Its quintuplet 3+2 Petzval system includes two ED elements and supports a 55 mm image circle, extending beyond a conventional full-frame sensor.
Manufacturer model: Askar FRA500 · Specifications checked against manufacturer data on 2026-11-04
