Common imaging train

Askar 65PHQ + 0.75× reducer + ASI2600MC Pro + filter drawer

Askar's 0.75× reducer for the 65PHQ brings the system to 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. Adding the reducer turns the PHQ into a fixed-spacing optic: now the stock extender answer applies.