Common imaging train

Takahashi FSQ-106EDX4 (prime focus) + ASI6200MM Pro + EFW 7×2" + OAG-L

Takahashi quotes a "metal back distance" for the FSQ-106EDX4 at prime focus: the distance from the rear face of the supplied camera adapter to the focal plane. The camera-side thread is not on the catalogue page, so add your Takahashi ring by its own length. 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 88 mm image circle swallows full frame; the long metal back distance is what needs a stack of extensions.