Fabiano

Thank you Ouroboros and Michaell!! Well, I have a flattener, that's why I am trying to get 55mm back focus. But I'll try with my current setup (I live in a cloudy area, so I need plenty of time yo make tests).

Hello all, I just bought a ZWO ASI 2600 and attached it to my EFW 36mm filter wheel using the 4 screws. How do I get the required 56mm back focus (55mm plus 1mm for the filter) with this setup? So far I have: telescope side - T2-M48 (16.5mm) - EFW (20mm) - ASI (17.5mm). This adds up to 54mm. The T2-T2 (2mm) is not used if the camera is directly attached to the EFW, so I am missing this 2mm. What am I doing wrong?