TS-Optics Full Format 0.8x Corrector for APO Refractors - M92x1 Connection - ADJUSTABLE

TS-Optics Full Format 0.8x Corrector for APO Refractors - M92x1 Connection - ADJUSTABLE

The 3" Photoline 0.8x reducer and corrector is optimized for full frame cameras and suitable for all apos from 102mm aperture - with integrated fine tuning for optimal working distance.

  • Optimally suited for large sensors (full frame and larger)
  • Connection thread on the telescope side is M92x1 male thread - adapters for focusers from 3" are available
  • The distance from the corrector to the camera is precisely adjustable with the camera connected for optimal field sharpness - Position is fixable
  • Triplet design with improved color correction - Special glass from Ohara (Japan)
  • Camera connection via M48x0.75 adapter with integrated female thread for 2" filter
  • Additional M54x0.75 thread for larger camera sensors - prevents vignetting due to M48
  • High-quality multi-coating, internal blackening and anti-reflective thread prevent reflections and ghost images
  • Dust caps for screwing on the M92 thread and M48 thread are included in the scope of delivery
Manufacturer : TS Optics
SKU : TSO-TSRED3
Price: 535.00 € incl tax 19% (Germany)
Estimated delivery time : 4-8 weeks
Product description

TS Photoline 3" Full Format 0.8x Corrector for APO Refractor Telescopes

The corrector is suitable for all refractors with 2-element and 3-element objectives from 102mm aperture, which are equipped with large focusers. The connection thread on the telescope side is a M92x1 male thread. Adapters to other threads, such as M68x1 are available. The flattener corrects the field of view and provides an even image to the edge. The focal length is reduced by a factor of 0.8x and the focal ratio is improved accordingly.

Adjust the corrector individually to your camera and refractor - without additional adapters

An essential part of the corrector is an integrated fine adjustment. By turning the knurled ring on the corrector, you can adjust the distance to the sensor to within fractions of a millimeter. Once you have reached the desired distance, fix it with the clamping screw. In this way, you can determine the optimum distance via test exposures with the camera connected, without additional adapters and tuning rings. The camera does not rotate during fine adjustment.

The following settings from the innermost position of the adjustment to the sensor are recommended:

  • TSCFAPO102 - 102 mm f/7 Triplet APO - 67.07 mm
  • TSAPO130F7-DEL - 130 mm f/7 Triplet APO - 63.46 mm
  • TSCFAPO130 - 130 mm f/7 FPL55 Triplet APO - 63.77 mm
  • TSAPO140 - 140 mm f/6.5 Triplet APO - 63 mm
  • TSAPO150-37 - 150 mm f/8 2-element APO - 60.61 mm
  • ESPRIT150 - 150 mm f/7 APO - 59.91 mm
  • TSAPO155f8 - 155mm f/8 FPL55 triplet APO - 59.81 mm


If you unscrew the M48 adapter, you gain another 10.5 mm of optical path from the M54x0.75 mount thread and you avoid the M48 bottleneck.

Application example - how do I set the distance?

Setting the correct distance is easy. You just have to know your telescope and of course the back focus of the camera with accessories. The back focus is the distance from the connection thread to the sensor. A typical back focus is 55 mm and the connection M48, exactly this distance we take as an example on a TSCFAPO130 (130mm f/7 FPL55 Apo).

  • The working distance according to the table is 63.77 mm (from the M48 thread).
  • Camera with accessories - flange focal distance 55 mm with M48 connection on the telescope side
  • Simply subtract the 55 mm from the 63.77 mm. This leaves 8.77 mm.
  • Turn the variable adjustment outward by 8.77 mm and fix the position with the set screw. You are already at the optimal distance and can start taking pictures.

Adapting the corrector to other refractors:

The corrector is suitable for all refractors with eyepiece extensions from 3". The adjustment is best done with test exposures.

  • Adjust the rough position using similar refractors.
  • Take a test shot, usually the coarse adjustment is sufficient. Focus optimally in the center.
  • If the edge stars are distorted from the inside to the outside, then increase the distance to the camera a little with the adjustment on the flattener.
  • If the edge stars are distorted in a crescent shape at the edge, i.e. they look like a short exposed pole shot, then reduce the distance a little.


You can do this with the camera mounted, so you will get the perfect distance for optimal stars in the field even with your telescope.

Adaption of the TSRED3 to your telescope

We recommend at least a 3" focuser for this corrector. This guarantees that the focuser will not cause vignetting. The corrector has a M92x1 male thread on the telescope side. It fits directly into the corresponding internal thread of the TSCF Apos with the 3.7" focuser, also into the TS 130mm f/7 Photoline DEL Apo and into the large 3.7" RPA focuser the corrector fits directly.

For other telescopes, such as our TSAPO140, Skywatcher ESPRIT and for APOs with the M68 thread connection on the focuser, we offer adapters.

Scope of Delivery:

  • 0.8x corrector
  • Adapter from M54x0.75 to M48x0.75 length 10.5 mm
  • Dust caps
Products specifications
CoatingMulticoated
Connection to telescopeM92 OD Thread
Connection to cameraM48x0.75 external thread
Reduction:0.8x reduction
Recommended distance from focal plane to connecting threadadjustable with non-rotating helical focuser