I want to use my 12" TPO RC for astrophotogrpahy using a sensor diagonal of 28.35mm (I also want to use OAG) so I'm sensitive to the need for a large image circle from the reducer. My favorite would be a 0.75 reducer but would look at anything between .8 and .5. The reducers suitable for an RC I've come across generally provide a small image circle of 15mm or so which won't do the trick.
The only reducer I've found right now is the "TS-Optics Optics 2" CCD Reducer 0.67x for RC & flatfield telescopes" from Teleskop service in Germany, I'm not sure if there is a US distributor or its quality.
Edited by pmacaree, 04 May 2021 - 01:59 PM.