The fast f/3.9 optical tube for your own mount!
The Bresser Messier 203/800 OTA (NT 203S) is the astrograph of the Messier line as an optical tube assembly. The fast f/3.9 optics gather a large amount of signal during short exposure times and are factory-prepared for a coma corrector and a 10:1 dual-speed focuser. The included solar filters also allow for safe solar observation. Via the Vixen-style dovetail, the tube clicks onto any mount with a standard Vixen clamp.


Fast parabolic optics
The parabolic 203 mm mirror collects over 800 times more light than the naked eye. With an 800 mm focal length (f/3.9), this is one of the fastest Newtonians in its class: ideal for nebulae and galaxies, and visually great for wide fields at low magnification. With the 26 mm eyepiece, you view at 31x. Only use the solar filter if it is undamaged and never look at the sun without certified protection.
Which mount fits this?
For astrophotography, tracking is required: the Bresser EXOS-2 EQ GoTo mount (998 euros) with ST-4 autoguider port is the logical basis. Purely visually, the Bresser EXOS-2/EQ-5 mount on tripod (539 euros) carries this tube just fine as well.
Included
- Newtonian optics 203/800 with parabolic primary mirror
- 2.5 inch Hexafoc focuser with 1.25 and 2 inch adapters
- SP 26mm eyepiece (1.25 inch)
- 8×50 viewfinder
- Vixen-Style Split Rings
- Solar filters
Featured accessories
A comma corrector from our Optical accessories at f/3.9 is the most important photo upgrade, along with the Bresser 1:8 microfocuser (99 euros). A Bresser laser collimator (74.90 euros) is indispensable at this focal ratio. For transport, the Oklop transport bag Newton 200/800 (119 euro).
For whom yes, for whom no
Well: astrophotographers who already have their mount and are looking for a fast deep-sky optical tube. Not: planetary observers; choose the 203/1200 or a Maksutov instead. Compare on the reflector page. Meer Bresser is on the merk page.
Specifications
| Optical design | Newtonian reflector, parabolic |
| Opening | 203 mm |
| Focal length | 800 mm (f/3.9) |
| Focuser | 2.5-inch Hexafoc, prepared for 10:1 reduction |
| Execution | Optical Tube Assembly (OTA) with Vixen-Style Dovetail |
| Supplied eyepiece | SP 26 mm |
| Prepared for | Coma corrector and fine-focus reduction |





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