151PHQ
Askar
From $4,499.00
2 stores
In stock
The Askar 151PHQ is a quadruplet astrograph refractor featuring a 151mm aperture and 1057mm focal length for an f/7 focal ratio, with an impressive Strehl ratio of 0.97 and almost no chromatic aberration. With a claimed 60mm image circle, the 151PHQ can handle sensors larger than full frame into medium format territory. As a quadruplet design with a built-in field flattener, it comes equipped for imaging right out of the box, and can be optionally reduced to f/4.9 with the Askar 0.7x Reducer for faster imaging that gathers the same light in less than half the time.
Specifications
| Tube Length (imaging mode, dew shield contracted) | 976.8 mm |
| Focal length | 1057 mm |
| Dovetail Plate Length | 300 mm |
| Reduced Focal Ratio (with 0.7x Reducer) | f/4.9 |
| Back Focus (Imaging Mode) | 78 mm |
| Weight | 13 lb |
| Strehl Ratio | 0.97% |
| Image Circle | 60 mm |
| Field Flattener | Built-in |
| Aperture | 151 mm |
| Focuser Size | 3.4 in |
| Central RMS Radius | 2 μm |
| Tube Length (imaging mode, dew shield extended) | 1164.3 mm |
| Focal ratio | f/7 |
| Optical design | Quadruplet with 2 ED elements |
| Reduced Focal Length (with 0.7x Reducer) | 740 mm |