TS Optics CCD 0.67x 2″ Focal Reducer for RC Telescopes at F/8
If you photograph with an RC telescope at F/8 and want a wider field of view without giving up image quality, this focal reducer from TS Optics is exactly what you need. It reduces the effective focal length to 67% of the original value. This noticeably widens the field of view and shortens the exposure time needed to reach the same brightness. The result is a flat, evenly illuminated image across the full sensor area - ideal for CMOS and CCD cameras as well as for the more demanding visual observer. The reducer is also designed as a flatfield corrector, so it combines focal reduction with field correction in one compact body.
Premium optical coatings - no ghost images
The focal reducer for RC telescopes features the highest-quality optical coatings available. These coatings effectively eliminate stray reflections and ghost images. In practice, even when imaging bright stars or planets near the edge of the field, you will not see unwanted artefacts that would otherwise spoil both the visual impression and your astrophotography results.
The clear aperture of 44mm provides sufficient light throughput even for larger sensors. At F/8, the fully illuminated circle reaches a diameter of 29mm - enough to cover most commonly used CCD and CMOS sensors without vignetting.
Connection and working distance
The reducer inserts into a standard 2″ focuser. On the camera side, it offers an M48x0.75 male thread, which is today the de facto standard for astrophotography accessories. On the telescope side, a 2″ filter thread is available, so you can easily place a broadband or narrowband filter in the optical path without any additional adapters.
The working distance of the reducer ranges from 70 to 90mm. The best results - the most even field illumination and the sharpest stars to the edges of the frame - are achieved at approximately 85mm from the reducer's exit plane to the sensor plane. It is important to set this distance carefully when assembling your imaging train. A distance that is too short or too long will reduce field correction at the edges.
Key specifications
| Parameter |
Value |
| Reduction factor |
0.67x |
| Designed for |
RC telescopes at F/8 |
| Clear aperture |
44mm |
| Fully illuminated circle at F/8 |
29mm diameter |
| Telescope side connection |
2″ barrel with 2″ filter thread |
| Camera side connection |
M48x0.75 male thread |
| Working distance |
70-90mm (optimum approx. 85mm) |
| Optical design |
Focal reducer + flatfield corrector |
| Coating |
Anti-reflection coating |
Who is this reducer for?
The TS Optics CCD 0.67x focal reducer is a practical, optically well-crafted accessory for anyone who wants to get the most from an RC telescope - whether for systematic imaging of nebulae and galaxies, or for occasional visual observation with a wider field of view. The combination of flatfield correction, anti-reflection coatings and a standardised threaded connection makes it a reliable companion for your telescope, even during a demanding observing session.
Main benefits at a glance
- Reduces focal length to 67% - wider field of view and shorter exposures
- Flatfield correction included - flat, sharp images from centre to edge
- Anti-reflection coatings - no ghost images, even with bright objects
- 44mm clear aperture - covers larger sensors without vignetting
- 29mm fully illuminated circle at F/8 - suits most CCD and CMOS sensors
- M48x0.75 camera connection - the current astrophotography standard
- 2″ filter thread on the telescope side - no extra adapters needed
- Working distance 70-90mm - optimum at approx. 85mm
