Hi! I'm trying to figure out a way to put together my ASI174MM, EFW mini and ZWO OAG in a way that will give me less than 55mm of back focus.
Currently:
174MM + T2/T2 + EFW mini + M42 adapter + OAG
17.5mm + 2MM + 20mm + 1mm + 16.5mm = 57mm
I want to connect this to a Skywatcher 0.85x FF/FR which needs 55mm of back focus. To the above image train I will also need to add an OAG to M48 adapter. I don't know which exact model will work best but it will add another 3-10mm of backfocus. The net result is I need to shorten this image train by at least 5mm.
1) is there a way to shorten the BF of the ASA 174MM? Is there or will there be a short profile adapter that would allow me to connect the camera directly to the EFW, dispense with the T2/T2 adapter and save several millimetres? Is there or will there be a faceplate similar to the 1600 that shortens the BF of the 174MM and allows a direct connection to the EFW?
2) Is there a 1mm deep T2/T2 adapter available (male to male?)
3) Once I've found a solution to the above problem I'll also need to get the sensor & OAG focus distances matched. In the above scenario I need to add 23mm to the OAG camera (a 120MM-S)
I hope this is possible.....if not I may have to look at a separate guider, or just not use the OAG on this scope.
Cheers!
