Common imaging train

ASI533MC Pro + M42 filter drawer

ZWO's 0.75× reducer for the FF65 asks for the standard 55 mm behind its M48 output. One-shot colour usually runs a single dual-band filter in a drop-in drawer instead of a wheel. The M42 drawer threads straight onto the camera and leaves a gap that one of the extenders in the camera box closes — once the filter glass is accounted for. The ASI533 ships with an 11 mm T2 ring on the body; leave it on and the 1" sensor makes bores a non-issue.