I am confused about the correct back focus.

tennyson

I have an EdgeHD 8" with f/7 reducer the required back focus is 105mm

ASI2600MC-P the back focus recommended is 55mm

So what is the correct back focus to use this camera with the Edge and f/7 reducer?

Thanks.

moson

Sorry we only have the solution of 55mm back focus.

Mabe you need other kinds of adapters to connect your telescope with the camera.

wvreeven

55 mm is the standard back focus for Canon and some other DSLR cameras, which is why manufacturers of flattener and reducers strive for that back focus as well. Not sure why ZWO put this on their website because the back focus is determined by the flattener or reducer, not the camera. In other words, follow the instructions of your EdgeHD.

Wouter

tennyson

Thanks Wouter, as a newbie it is great to learn from others.