The classic f/10 refractor as a standalone tube, with solar filters!
The Bresser AC 90/900 Messier OTA is the classic all-around refractor for your own mount. The f/10 design keeps chromatic aberration well under control: the Moon, planets, and double stars appear calm and sharp. The included solar filters also allow for safe solar observation.


Classic f/10 achromatic
The 90 mm lens captures approximately 165 times more light than the naked eye. With the 26 mm eyepiece, you get 35x magnification; consider approximately 180x as the maximum. The integrated dew shield keeps the lens free from dew for longer. Use solar filters only if they are undamaged and never look at the sun without certified protection.
Which mount fits this?
The Bresser EXOS-1/EQ-4 mount with tripod (€379) carries this tube with ease; a sturdy azimuthal mount with a Vixen clamp also suffices visually. Via the Vixen-Style dovetail, the tube fits any mount with a standard Vixen clamp.
Included
- Achromatic optics 90/900
- SP 26mm eyepiece (1.25 inch)
- 6x30 binocular
- 90 degree star diagonal
- Integrated lens hood
- Vixen-Style Split Rings
- Solar filters
- Smartphone camera adapter
Featured accessories
The Bresser Plössl 10 mm eyepiece (90x, 29 euros) is the medium magnification. An Omegon Premium moon filter (19.90 euros) dims the moonlight. For transport, the Shield transport bag for refractors up to 100/900.
For whom yes, for whom no
Suitable for: anyone looking for a maintenance-free all-rounder for the Moon, planets, and Sun on an existing mount. Not suitable for: deep-sky photographers; the small aperture and f/10 are not intended for that. Compare to refractor page. Meer Bresser is on the merk page.
Specifications
| Optical design | Achromatic refractor (two-lens) |
| Opening | 90 mm |
| Focal length | 900 mm (f/10) |
| Focuser | 1.25 inches |
| Execution | Optical Tube Assembly (OTA) |
| Supplied eyepiece | SP 26 mm |
| Special feature | Including sun filters and lens hood |






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