Askar FRA400C APO Astrograph
The Askar FRA400C is a versatile quintuplet APO astrograph designed for both astrophotography and visual use. With a 72 mm aperture, 400 mm focal length at f/5.6, and ED glass elements, this telescope delivers crisp, flat-field images across a large 44 mm full-frame sensor.
Key Features
- Aperture: 72 mm
- Focal Length: 400 mm (f/5.6)
- Optical Design: Quintuplet APO (Petzval)
- Image Circle: 44 mm (full-frame coverage)
- Focus: 2.5″ dual-speed rack-and-pinion focuser
- Back Focus: 140 mm
- Use Case: Wide-field astrophotography and observation
Why Choose the FRA400C?
The FRA400C’s Petzval optical design eliminates the need for a separate field flattener, ensuring sharp stars across the entire frame. This makes setup quicker and easier, saving valuable imaging time under the night sky.
Ideal For
- Wide-field imaging of nebulae and star clusters
- Full-frame astrophotography
- Astrophotographers seeking a compact, flat-field refractor
The Askar FRA400C is a superb balance of portability, optical performance, and convenience, making it an excellent choice for beginners and advanced imagers alike.
Specifications
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FRA400C Parameters |
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Aperture size |
72mm |
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Focal length |
400mm |
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Focal ratio |
f/5.6 |
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Objective lens |
Quintuplet dual ED air-spaced APO |
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Format specifications |
44mm |
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Aperture blades |
17 pieces |
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Graded Aperture |
f/5.6-f/22 |
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Closest Focus Distance |
5m |
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Focusing mode |
Manual focus |
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Filter Diameter |
M82 |
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Total length |
370mm (inclulding dew shield); 420mm (without dew shield) |
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OTA weight |
2.68kg |
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Total weight (including handle & dovetail plate) |
3.18kg |
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Rear-end adapter |
M72/M54/M48(with M48×0.75 filter thread) |
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Rear-end connection distance |
Support 50-60mm range (Recommended connection length is 55mm) |
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Standard package items |
1.25inch/2inch adapter,a manual |
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Product Size Diagram |



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FRA400C AFkit Electronic Focuser Assembly Diagram |


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Optical Path Diagram |

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Spot Diagram |

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Longitudinal Aberration |

Video
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