Takahashi SKY-90 specifications
Optical specifications
| Spec. | SKY-90 |
|---|---|
| Optical design | Fluorite Doublet |
| Optical mounting | Air spaced (Fluorite in front) |
| Optical coatings | Fully Multi-Coated |
| Aperture | 90mm |
| Standard | |
| Focal length | 500mm |
| Focal ratio | F/5.56 |
| Resolution | 1.29" |
| Limiting magnitude | 11.5 |
| Light grasp | 165x |
| Image circle | NA |
| Photo field | NA |
| With reducer | |
| Focal length | 407mm |
| Focal ratio | F/4.5 |
| Image circle | 45mm |
| Photo field | 6.3° |
Mecanical specifications
Longitudinal view (distance in mm)
| Spec. | SKY-90 |
|---|---|
| Tube length | 480mm/560mm 80mm retractable dew shield |
| Tube diameter | 95mm |
| Tube weight | 3.2kg |