| OPTICAL TUBE INFO: | |
| Optical Design | Rowe-Ackermann Schmidt Astrograph |
| Aperture | 279mm (11″) |
| Focal Length | 620mm (24.4″) |
| Focal Ratio | f/2.2 |
| Central obstruction diameter | 114mm (4.48″) (41% of aperture diameter) |
| Light Gathering Power (Compared to human eye) | 1588x |
| Resolution (Rayleigh) | 0.49 arc seconds |
| Resolution (Dawes) | 0.41 arc seconds |
| Image Circle | 43.3mm (1.7″) Ø , 4.0° |
| Useable field | 52mm (2.04″) Ø , 4.8° only minimal performance loss at edge of FOV |
| Wavelength range | 400 – 700 nm |
| Spot size | < 4.4 μm RMS across FOV |
| Optical Coatings | StarBright XLT |
| Off-axis Illumination | 83% at 21mm (.82″) off-axis |
| Optical Window | 68mm (2.67″) Ø |
| Back focus with included camera adapter | 55mm (2.16″) |
| Back focus from top of threaded collar | 72.8mm (2.86″) |
| Optical Tube | Aluminum |
| Optical Tube Length | 838.2mm (33″) |
| Optical Tube Diameter | 330.2mm (13″) |
| Focuser | Ultra-Stable Focus System |
| Finderscope | Not included |
| Optical Tube Weight | 43 lbs (19.5 kg) |
| Other Features | Ventilation fan, dual dovetail mounting bars |
| Included items | 42mm (1.65″) T-thread camera adapter | 48mm (1.89″) camera adapter | Dust cover | Fan battery pack |
| Dovetail | CGE Dovetail Bar |
