Askar FRA500 Quintuplet Flatfield APO Astrograph
2 266,00 €
90mm f/5.6 quintuplet flatfield astrograph with 500mm focal length. Built-in flat-field correction bridges the gap between the FRA400 and FRA600.
Description
<![CDATA[The Askar FRA500 is a 90mm f/5.6 quintuplet flatfield astrograph from the popular FRA (Flat-field Refractive Astrograph) series. With 500mm focal length and built-in flat field correction, it bridges the gap between the compact FRA400 and the larger FRA600.
The quintuplet optical design delivers an exceptionally flat field and outstanding chromatic correction, making it a true imaging-first instrument. The faster f/5.6 focal ratio compared to the PHQ series means shorter exposure times, ideal for capturing faint nebulae and extended objects.
The FRA500 can also serve as a high-quality telephoto lens for daytime photography. Its versatile design accepts a wide range of cameras and accessories.
Key Features
- Quintuplet optical design with built-in flat field correction
- 90mm aperture, 500mm focal length (f/5.6)
- Fast focal ratio for shorter exposures
- Suitable for astrophotography and daytime photography
- Each unit individually optically tested
- Compatible with full-frame sensors
Specifications
| Aperture | 90 mm |
|---|---|
| Focal Length | 500 mm |
| Focal Ratio | f/5.6 |
| Optical Design | Quintuplet flatfield |
| Field Flattener | Built-in |
| Brand | Askar |
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Explore these guides from our Astro Wiki to learn more about this type of equipment:
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