Takahashi Mewlon specifications
Optical specifications
| Spec. | Mewlon-180 | Mewlon-210 | Mewlon-250 | Mewlon-300 |
|---|---|---|---|---|
| Optical design | Dall-Kirkham (Cassegrain) | |||
| Effective aperture | 180mm | 210mm | 250mm | 300mm |
| Primary mirror diameter (focal length) | 180mm (F/3) | 220mm (F/2,9) | 260mm (F/3) | 310mm (F/3) |
| Secondary mirror diameter (amplification) | 54mm (x4) | 65mm (x4) | 70mm (x4) | 95mm (x4) |
| Secondary obstruction | 0,33 | 0,32 | 0,28 | 0,32 |
| Standard | ||||
| Focal length (at prime focus) | 2160mm | 2415mm | 3000mm | 3572mm |
| Focal ratio (at prime focus) | F/D 12 | F/D 11,5 | F/D 12 | F/D 11,9 |
| Resolution | 0,64" | 0,55" | 0,46" | 0,40" |
| Limiting magnitude | 13 | 13,4 | 13,8 | 14,2 |
| Light grasp | 661x | 900x | 1275x | 1836x |
| Image circle | 16mm | 18mm | 21mm | 25mm |
| Back focus | 210mm | 210mm | 210mm | 210mm |
| Eyepiece holder(s) | 50,8mm/31,75mm | 50,8mm/31,75mm | 50,8mm/31,75mm | 50,8mm/31,75mm |
| With reducer | ||||
| Focal length | 1763mm | 1961mm | 2307mm | 2739mm |
| Focal ratio | F/D 9,8 | F/D 9,3 | F/D 9,2 | F/D 9,1 |
| Image circle | 36mm | 39mm | 42mm | 42mm |
| Photographic field | 1,2° | 1,2° | 1° | 45' |
Mecanical specifications
Mewlon view
| Spec. | Mewlon-180 | Mewlon-210 | Mewlon-250 | Mewlon-300 |
|---|---|---|---|---|
| Tube length | 640 mm | 700 mm | 850 mm | 1094 mm |
| Tube diameter | 210 mm | 244 mm | 280 mm | 324 mm |
| Tube weight | 6 kg | 8 kg | 12 kg | 26 kg |