Lightweight Dobson Telescopes And High Quality Parabolic Mirrors - Made in Germany!
For a few months only: reduced prices for the Infinity NL model series
20"f/3 and 25"f/3 Dobsonian Telescopes: Technical Specifications
| Optics | 20 Inch | 25 Inch |
| Primary Mirror | 500/1650mm | 635/2000mm |
| Focal Ratio | f/3.30 | f/3.15 |
| Thickness of Primary | 31mm | 35mm |
| Weight of Primary | 11.6 kg | 20.3 kg |
| Strehl Ratio Primary | S > 0,85 | S > 0,80 |
| Interferom. Test Certificate | inclusive | inclusive |
| Faintest Star @ V=200x | 16.2mag | 16.5mag |
| Faintest Star @ V=350x | 16.6mag | 17.0mag |
| Rayleigh Resolution Limit | 0.23" | 0.18" |
| Secondary Mirror | 120mm | 160mm |
| Wave PV | lambda/12 | lambda/10 |
| Obstruction | 24% | 25% |
| Mechanics | 20 Inch | 25 Inch |
| Transport Mode 1 | 65x66x31cm | 78x78x35cm |
| Transport Mode 2 | 65x66x56cm | 78x80x68cm |
| Transport Mode 3 | 65x70x74cm | 78x84x85cm |
| Total Weight of Telescope | ~ 40 kg | ~ 63 kg |
| Weight of heaviest part | ~ 22 kg | ~ 36 kg |
| Weight of Mirror Box | ~ 10 kg | ~ 16 kg |
| Thickness of trusses | 20 mm | 24 mm |
| Length of trusses | 106 cm | 134 cm |
| Viewing Height Zenith | 152cm | 182cm |
| Attachments | 20 Inch | 25 Inch |
| Focuser | 2" Baader | 2" Baader |
| Reduction Ratio | 1:11 | 1:11 |
| Secondary Heating | inclusive | inclusive |
| Accessories | 20 Inch | 25 Inch |
| Filter Slide | optional | optional |
| Digital Setting Circles | optional | optional |
| Counterweight 1kg/2kg | optional | optional |