Common imaging train

Sky-Watcher Esprit 150 + 0.77× reducer + ASI6200MM Pro + EFW 7×2" + OAG-L

The 0.77× reducer for the Esprit 150 is a 55 mm M48 optic whose stated image circle does not reach the full-frame diagonal — the tool says so rather than pretending. Full-frame mono: ZWO only recommends 2" wheels for the 43 mm diagonal, the camera wears its M54 tilt plate, and the wheel and OAG-L bolt on with screws rather than threads. Every bore in this train has to clear the diagonal. The spacing works; the stated image circle does not reach the diagonal, and the tool says so rather than hiding it.