Quote:
Originally Posted by Bassnut
This might be a good reason for a secondary focuser 
the cam-filterwheel-MOAG-AO8-rotator and adaptor hell, took up 8.2" of back focus, no spacers, and the optimum BFD is 8.0", so im over already.
If I had to add a prime focuser, id be stuffed.
I havent got it all working yet, I got the rotator-MOAG-adaptor farm today, it just cant be that easy can it, oh no  .
Im posting a pic now, because if being 0.2" away from the BFD is no good, the whole lot goes in the bin . |
Hi Fred,
I know RCs have an optimum mirror spacing but I doubt it is that sensitive.
For one thing they universally employ a secondary focuser which changes that distance quite a bit.
Hard to say for sure as I didn't image on my 12.5 without using the secondary focuser but a lot my images looked the same as others
using 12.5 inch RCs. It didn't seem that critical certainly not .2 of an inch.
Greg.