TS 0.8x Corrector Reducer for Ritchey Chretien Telescopes - M68 connection

About this product

Model:  ts_tsrcred
Part Number:  TSRCRED

TS 0.8x Focal Reducer for Ritchey Chretien Telescopes 10" and Larger

TS offer this 0.8x Focal Reducer and Corrector suitable for full-format sensors.

Note: It works with 3" and larger focusers, so it is unsuitable for the 2" Monorail focuser on smaller RC telescopes. 

Pure telecompressors, like the CCDT67 from Astro Physics, reduce the focal length without correcting the image field. The result is aberrations visible (astigmatism) in the corners. The larger the sensor, the more pronounced the aberration.

The TSRCRED is designed especially for the image field of f/8 RC telescopes. Thus, it eliminates the aberrations entirely. The results are sharper, pinpoint stars and easier focusing.

This reducer is also the only choice for full frame size sensors that can be used with our StellaLyra RCs from 10" aperture upwards equipped with large focusers, such as TSFOCR30S.

Adapting the TSRCRED to the telescope:

You have two possibilities for adapting to your RC telescope. You can thread the corrector to the focuser or countersink it into the drawtube if you have less than 135 mm working distance.

  •  Adaption via the female M68x1 thread at the telescope side:

           Via suitable adapters, you can attach the corrector to any focusers from 2.5" upwards. You only need to provide the focuser with a male M68x1 thread at the camera side. Please note that you need a minimum of 135 mm working distance from the male thread.

  •  Adaption with countersinking the corrector into the draw tube at the same time:

           If there is less back focus, we recommend countersinking the corrector into the drawtube.
           Thus, the necessary back focus is reduced to less than 100 mm. Suitable adapters. For focusers with the female M78x1 thread, like the TSFOCR30S, TS already offer a suitable adapter (#M78a-M68a).

Adapting the camera to the TSRCRED

The working distance from the male M68x1 thread at the camera side is 82 mm. Thus, you have enough space for individual adaptions or accessories like off-axis guiders. The male thread is not considered for the working distance, as it disappears into the connection adapter.


The corrector and focal reducer is designed especially for Ritchey-Chrétien telescopes. It shortens the focal length while correcting the image field at the same time.

  • Connection at telescope side: M68x1 thread (female)
  • Connection at camera side: M68x1 thread (male)
  • Diameter 74 mm - the corrector can be sunken into 3" focusers
  • Working distance from the male M68x1 thread: 82 mm
  • The focal length is shortened by a factor of 0.8x, and the speed is increased correspondingly.
  • In addition, the corrector eliminates the field aberrations of f/8 RC telescopes. It works with all f/8 RC telescopes, for example, StellaLyra, TS-Optics, AstroTec, CFF, and Officina Stellare.




Type Reducer
Focal Reduction 0.8x
Thread Scope Side M68x1 thread (female) - length 6 mm
Thread Camera Side M68x1 thread (male) - length 5 mm
Diameter 74mm
Height 34mm
Number of Elements 3 Elements
Coating Multi Coated


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