The best value, highest quality 250mm lens you will find for your camera.
51 mm lens, in a sleek Petzval design, using Synthetic Fluoride (FPL53 and FPL51) glass for a full-frame flat field image. The optical quality provides exceptional performance at a fast focal ratio of f/4.9.
Filter Adapter allows use of 48mm filters. Focusing is made easy with a bahtinov mask integrated into the lens cap.
| Aperture |
51 mm (2") |
| Camera/Eyepiece Connection |
Male M48x0.75 |
| Dawes Limit |
0.46 arcseconds |
| Focal Length |
250 mm |
| Focal Ratio |
f/4.9 |
| Glass Type |
FPL-53 and FPL-51 |
| Highest Useful Magnification |
102x |
| Light Gathering Power |
53x |
| Limiting Magnitude |
12.3 |
| Optical Design |
Petzval |
| Tube Color |
Red |
| Tube Diameter |
84mm |
| Tube Weight |
5.25 lbs |
| Dew Shield Outer Diameter (for soar filter sizing) |
84mm |
Note: You may need a riser block to use the RedCat 51 on some dual-saddle mounts. The focuser impacts the plate on the Celestron Advanced VX mount saddle that accepts both CG5 and CGE plates. The focus knob does not impact the Celestron CGX saddle, or the iOptron CEM70 and GEM45 / CEM40 dual-saddle plates. The focuser knob does not impact the SkyWatcher EQ6 and HEQ5 mounts.
See It In Person - On Display In Our Showroom!
Qualifies for Free Ground Economy Shipping (CONUS Only)