Askar FRA400 The Askar FRA400 is a 72 mm f/5.6 astrograph with a 400 mm focal length. Its five-element Petzval-like design uses two ED elements and provides a 44 mm image circle for full-frame photography.
Manufacturer model: Askar FRA400 · Specifications checked against manufacturer data on 2026-11-04
The Askar FRA400 is a 72 mm f/5.6 astrograph with a 400 mm focal length. Its five-element Petzval-like design uses two ED elements and provides a 44 mm image circle for full-frame photography.
The native optical design incorporates field flattening. There is no additional flattener to space at 55 mm: fit the imaging train within the available connection allowance and focus the telescope. Askar publishes 140 mm from the M68×1 rotator reference to the focal plane.
A 3-inch rack-and-pinion focuser provides 1:10 fine adjustment and a 360° rotator. The rear assembly offers M68×1, a conical M68-to-M48 adapter and 2-inch/1.25-inch visual connections. A retractable hood and multifunction tube rings provide practical mounting options.
The standard package includes rings, handle, dovetail and conical adapter. Askar lists 317 mm overall length, 2.56 kg OTA and 2.88 kg with rings and dovetail. The separately available matching reducer changes the system to approximately f/3.9 and requires its own specified camera spacing.
Askar manufacturer documentation
The detailed description and technical table identify a quintuplet dual-ED design; a promotional icon incorrectly says quadruplet. Native 140 mm connection allowance is measured from the M68×1 rotator reference, not a mandatory 55 mm reducer spacing.
| Manufacturer accessories | A pair of tube rings, a handle, a dovetail plate, a M68-M48 conical adapter ， an inspection list, a manual |
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Data sheet
Askar FRA400 The Askar FRA400 is a 72 mm f/5.6 astrograph with a 400 mm focal length. Its five-element Petzval-like design uses two ED elements and provides a 44 mm image circle for full-frame photography.
Manufacturer model: Askar FRA400 · Specifications checked against manufacturer data on 2026-11-04
