OTA · 2003–
Takahashi BRC-250
Key specifications
| Aperture | 250 mm |
|---|---|
| Focal length | 1268 mm |
| Focal ratio | f/5 |
| Optical design | Ritchey-Chrétien |
About
250 mm Baker-Ritchey-Chrétien flat-field astrograph, 1268 mm composite focal length at f/5, with hyperbolic primary and secondary plus a two-element corrector for a large flat ~100 mm image circle. Designed for medium-format film/CCD astrophotography; predecessor to the CCA-250.