ASKAR FRA300 PRO
- Brand: Askar
- Product Code: ASK-FRA300PRO
Askar FRA 300 f/5 Pro
The Askar FRA 300 f/5 Pro is a professional apochromatic Petzval quintuplet with an aperture of 60mm and a corrected field of 44mm in diameter..
The lenses are assembled in two groups: an air-spaced triplet on the front and two far-separated corrective lenses in the rear. The objective lens includes one Extra Low Dispersion lens for superb chromatic correction.
Differently from standard ED refractors, the Askar 300 features a Petzval design that does not require to set the sensor to a specific distance to the last lens. That leaves the freedom to use any filter wheel, any off-axis guider or accessory without any worry to calculate the correct distance from the flattener.
With a large 44mm corrected image circle and a fast focal ratio of f/5, this is the perfect astrograph for the advanced astrophotographer. The large rack and pinion 2.5" focuser has a high payload capacity, it can be rotated 360° to perfectly frame the subject and it has a reduction gear of 10:1 for precise focusing.
All the lenses are fully multi-coated and the tube is internally blackened to reduce reflections and absorb stray light. The tube is made of aluminium, the rack and pinion focusing mechanism of brass and the mechanical components are engineered to provide the best rigidity, performance and durability.
Askar Telescope | |
Optical design | Apochromatic Quintuplet air spaced with one ED element |
---|---|
Objective diameter | 60 mm |
Focal length | 300 mm |
Focal ratio | f/5 |
Mount attachment | 300 mm Vixen style bar |
Focuser | Rack & pinion dual speed (10:1) 2.5" diameter |
Tube weight | 3.12 kg (including tube rings and dovetail bar) |
Dew shield diameter | TBD |
Tube diameter | TBD |
Connections | M54 x 0.75 male, M48 x 0.75 male, M42 x 0.75 male |
Flattener/reducer back focus | 71 mm from base of M54 & M42 threads, 67 mm from base of M48 thread |