Askar Apochromatic refractor AP 72/400 FRA400C Astrograph (86029)

The ASKAR FRA400 is a compact Petzval-type apochromatic refractor with a 400 mm focal length, f/5.6 focal ratio, and a 72 mm aperture. Its five-element optical design includes two ED glass elements, ensuring excellent correction of chromatic aberration. The optical system is fully corrected for cameras up to full-frame format, making it well suited for high-quality astrophotography.

The extendable dew shield provides effective protection against stray light and dew. A robust, oversized focuser supports even heavy camera setups and allows precise focusing thanks to its fine reduction mechanism. The telescope offers 2-inch, 1.25-inch, and M68×1 connections, ensuring broad compatibility with accessories. An M48×0.75 adapter is included, ideal for cameras requiring a 55 mm back focus. To access the internal M48 female thread for 2-inch filters, simply remove the adapter.

Primarily designed for astrophotography, yet versatile for observation
Although optimized as an astrograph, the ASKAR FRA400 can also be used for visual observation. The generous working distance allows the use of 2-inch star diagonals, transforming the instrument into an excellent telescope for astronomical viewing and even landscape observation. All standard 2-inch and 1.25-inch accessories are supported.

Optional speed increase to f/3.9
While the native f/5.6 focal ratio is already fast, the optional FRA400 reducer further increases the speed to f/3.9, effectively cutting exposure times in half. With the reducer installed, the focal length is shortened to 281 mm, making it particularly attractive for wide-field astrophotography.

Optical specifications

• Optical design: Apochromatic refractor (Petzval)

• Aperture: 72 mm

• Focal length: 400 mm

• Focal ratio: f/5.6

• Resolving power: 1.92 arcseconds

• Limiting magnitude: 11.1

• Light-gathering power: 110×

• Maximum useful magnification: 144×

• Fully corrected image circle: 44 mm

Mechanical specifications

• Tube weight: 2.56 kg

• Transport length: 317 mm

• Internal stray-light baffles: Yes

• Dew shield: Retractable

Focuser and connections

• Focuser type: Helical

• Eyepiece connection: 2-inch

• Camera-side threads: M72, M54, M48

• Back focus: 55 mm

• Free aperture: 76 mm

• Rotatable focuser: Yes

• Filter thread: Yes

• Motorized focuser: No

Mounting and accessories

• Mount type: Optical tube assembly (OTA only)

• Dovetail: Vixen-style

• Tube rings: Included

• Eyepiece adapter: 2-inch / 1.25-inch

• Finder base: Vixen / SkyWatcher standard

Application areas

• Astrophotography: Yes

• Nebulae and galaxies: Yes

• Moon and planets: Yes

• Nature observation: No

• Solar observation: No (only with a suitable solar filter)

Recommended user level

• Beginners: No

• Advanced users: Yes

• Observatories: No