2" Reducer and image corrector for Schmidt-Cassegrain Telescopes
... 0,8x Reducer and flattener for all f/10 and f/11 Schmidt-Cassegrains


Schmidt-Cassegrains are one of the most popular telescope models among advanced amateur astronomers. They have several features that would make them the ideal telescopes for astro imaging, however there used to be one big problem: Until recently there was no good quality image corrector on the market! We checked all correctors we could get our hands on, but none of them were satisfactory for today's cameras. Those correctors with a suitable image quality that did exist provided a too narrow back focus distance, making the use of off axis guiders and similar accessories impracticable.

The design of this correctors was made in Germany for us to our specifications. We are proud to offer this unique product that is ideally suited for high resolution cameras up to about 30mm sensor diagonal. The corrector works on all common f/10 and f/11 Scmidt-Cassegrains.

Advantages and features of the 0.8x TS SC Corrector:

-- 2" body diameter - the corrector can be inserted completely in a 2" focuser or a 2" visual back adaptor.
-- can be adapted to all Schmidt Cassegrains from 6" to 16" aperture.
-- M48 filter thread on both sides. A large selection of adaptors is available for virtually all applications and setups.
-- 97.5mm back focus behind the base of the M48 male thread. This provides sufficient space for additional accessories such as off axis guiders or filter wheels.
-- high performance three-lens design, very good coating. No ghost images or internal reflections.

The TS SC Corrector can be used on all Schmidt Cassegrain Telescopes:

The corrector was designed for optimum results with all common Schmidt-Cassegrain telescopes. It removes field curvature and coma. The result is a superb image quality throughout the full photographical field of view. Theoretically the corrector could even be used visually if you keep the right distance between the corrector and the field stop of the eyepiece.

Practical tip from Teleskop Service - flattened and perfect adjusted field Schmidt Cassegrain telescopes often do not show a perfect plain field due to the movable main mirror. Simple f/6,3 reducer have not been precise enough to show that. Using this 0,8x reducer and trying to get the best performance right to the very corners, we recommend to use the TS tilting unit which comes with a T2 or M48 adaption. This is how it works - with starfield testphotos: Due to the tilted field of the SC telescope You will receive differing focus areas in each corner. That means that when zooming in one corner, at least one of the others is not perfectly focussed. The difference is small and also be corrected with image-processing but the best is, when already Your raw material is in perfect condition. Define the Orientation of the bad corner with a testshot. Now use the screw pairs to slightly change the camera positiont to that direction. Immediately You will recognize the difference. If Your photo gets worse, then go back and use the screw pair on the other side until Your image quality increases. After around 1 hour You'll have a perfect result. Very important is, to remember the reducers position. A small mark on the focuser and the reducer really makes sense. ................ Link to TS M48 tilting unit

2" Barrel Adaptation instead of SC Thread Adaptation:

The classic SC thread (2" UNC thread) proved to be unsuitable for our applications. We designed the corrector with the 2" filter thread (M48x0.75). As a result, the corrector can be sunk into a focuser or visual back adaptor. Most astro imagers use 2" Crayford focusers for smoother focusing and to avoid the image shift problem inherent with most Schmidt-Cassegrains.

You can easily attach various accessories to the corrector by means of the TS and Baader adaptor ranges. Contrary to the also popular T2 thread the M48 thread allowed for a much larger clear aperture.