The Askar 91F 91 mm f/6.7 quadruplet APO optical tube assembly is designed for astronomy enthusiasts and professional astrophotographers seeking flawless optical and mechanical performance. This compact, ultra-portable telescope is an excellent choice for both visual observation and astrophotography.
With a 91 mm aperture and 609 mm focal length, the Askar 91F OTA has an f/6.7 focal ratio. The colour-corrected ED triplet objective and integrated field flattener ensure distortion-free, precise sharpness across the entire field of view. The telescope provides a 44 mm image circle, making it ideally suited for imaging with full-frame sensors. Like Petzval optical systems, it eliminates the need to calculate backfocus. With the optional 0.75x focal reducer, it becomes an extremely fast f/5 astrograph.
The dual-speed 3" rack-and-pinion focuser enables precise adjustment and can be rotated through 360°. The M64, M54 and M48 threaded connections on the focuser provide broad compatibility with a wide range of accessories and cameras.
Thanks to the practical tube rings, Vixen dovetail bar and carry handle, the Askar 91F can be easily mounted and transported. The telescope also features two finder shoes for attaching additional accessories. The retractable dew shield helps protect the lenses from moisture and dew.
The Askar 91F OTA weighs only 3.92 kg and measures 513 mm in length, making it ultra-portable and an ideal choice for hiking or locations where easy transport is essential. The Askar 91F quadruplet APO OTA delivers outstanding performance among premium optical solutions and is an excellent companion for astronomical adventures.
Particularly useful for nature observers, the standard package includes an Amici prism providing an upright image, as well as 20 mm and 8 mm eyepieces offering 30x and 76x magnification.
Key features of the Askar 91F apochromat:
- Aperture: 91 mm
- Focal length: 609 mm
- Focal ratio: f/6.7
- Colour-corrected ED triplet objective and field flattener lens
- 44 mm image circle, full-frame compatible
- 3" dual-speed, 360° rotatable focuser
- Camera connection: M64, M54 and M48
- Tube rings, dovetail bar, carry handle
- Two finder shoes on the tube
- Retractable dew shield
- Weight: 4.5 kg (with tube rings and dovetail bar)
- Length: 513 mm
- Ultra-portable travel telescope for visual and photographic use
- 1.25" Amici prism
- 20 mm and 8 mm eyepieces
