Quote:
Originally Posted by gregbradley
I looked up the MPCC specifications and as pointed out you need to have it set 55mm from the back metal flange of the MPCC
to the top plane of the chip. This is called metal back distance (the last metal edge of the corrector to the surface of the CCD chip).
All correctors/flatteners have a metal back distance. You then need to have the correct length adapter to make sure your MPCC and chip are set at that distance. If one is not available standard you'll have to get one made up. Hopefully QHY sells accessories or Baader does.
There is mention on the Baader site about a T2 system.
Here is the link to Baader's writeup:
http://www.scopecity.com/detail.cfm?ProductID=5515
The unit does not operate properly at the wrong spacing.
Greg. |
Thanks Peter and Greg for the advice.
Yep I had read about the 55mm distance but I just threw it straight
on to get an idea of the 'uncorrected coma'/ rough FOV of my 12".
I knew it was going to have some but I didn't quite think this much
If I am correct I need to knock up a quick spacer today on the lathe
with the spacing being 35 mm as shown below in red mm.
The QHY-8 has a CCD/film plane depth of 20mm from the face
of the 2" nosepiece.
I hope I have this right.
I have 2 options for threads....42mm male one end, 48mm female other.
OR
42mm male one end, 42mm female the other (with spacer/lock ring
removed on the MPCC)
Steve