Askar 71F Flat-Field Astrograph
Askar 71F Flat-Field Astrograph: a lightweight and compact flat-field quadruplet astrograph, offered at a very competitive price and suitable for both visual observation and astrophotography.
Askar 71F Flat-Field Astrograph
The Askar 71F is a flat-field apochromatic refractor featuring a 71 mm aperture, a focal length of 490 mm, and a native focal ratio of f/6.9.
The Askar 71F employs an air-spaced four-element apochromatic objective with one ED glass element, effectively reducing chromatic aberration. It supports a 44 mm image circle (suitable for sensors up to full-frame format), delivering excellent performance and well-controlled star shapes.
The Askar 71F features a field-correcting lens integrated within the optical tube assembly, eliminating the need for complex calculations to determine the precise camera position. Once the imaging accessories are connected, users can begin capturing images simply by achieving focus. This further reduces costs while enhancing the overall imaging experience.
Designed with practicality and versatility in mind, the weight and dimensions of the Askar 71F were carefully considered during the design phase, making it easy to transport and use. The Askar 71F OTA weighs only 2.5 kg, with a total weight of 3 kg including tube rings and dovetail plate.
The Askar 71F is versatile, as it supports both visual observation and astrophotography.
The Askar 71F also comes standard with a photographic extension tube, including M48x0.75 and M54x0.75 adapters, and features a built-in 2" filter thread for convenient imaging setups. Whether connecting a standard DSLR or a professional astronomical camera, it is very easy to use. When users go out, they can directly attach imaging accessories to capture the stunning view at any time.
The mechanical design of the Askar 71F follows Askar's philosophy of accounting for user habits while minimizing unnecessary costs.
The Askar 71F dew shield is retractable, further reducing the overall length and improving portability. The entire optical tube is manufactured using high-quality CNC machining. The inner surface of the dew shield is fully coated with matte black paint to effectively reduce stray light reflections. The blue and white color scheme gives the telescope a refined appearance.
On the focuser housing of the Askar 71F there is a finder base mounting slot. In addition, two finder bases are located on both sides of the focuser, which not only eliminates the need for disassembly when changing the telescope's orientation, but also provides additional mounting positions for other astronomical accessories.
Regarding the focuser, the Askar 71F is equipped with a 2.4" dual-speed rack-and-pinion focuser, featuring a 1:10 fine adjustment ratio and a 360° graduated field rotator at the rear end for precise angle adjustment.
The Askar 71F dovetail plate is a standard 230 mm Vixen/GP-style rail, with 1/4" and 3/8" threaded holes for direct tripod mounting.
|
Technical Specifications |
||
|
Aperture |
71 mm |
|
|
Focal length |
490 mm |
|
|
Focal ratio |
f/6.9 |
|
|
Optical design |
Air-spaced quadruplet with one ED element |
|
|
Image circle |
44 mm |
|
|
Back focus (fully racked in focuser) |
Imaging mode: |
Visual mode: |
|
Total length |
372.5 mm (focuser fully racked in with 1.25" eyepiece holder) |
|
|
OTA weight |
2.5 kg |
|
|
OTA weight with rings and dovetail |
3.0 kg |
|
|
Included imaging adapter threads |
M64.0.75-M54.0.75 |
|
|
Included items |
An Askar 71F optical tube, a pair of tube rings, handle, 230 mm Vixen-style dovetail plate, set of imaging adapters |
|
Product Size
System Chart
Focuser locking screw installation
Focuser motor installation
Optical Path Diagram
Spot Diagram
Images
| Product Status | New |
|---|---|
| Package width | 23 cm |
| Package height | 23 cm |
| Package depth | 51 cm |
| No. of parcels | 1 |
