Hi Brent and Bojan,
We have a lot of discussion or comments about this on the Swedish forum. Now I clearly see why it's so complicated to have a coma corrector and long backfocus on a Newton telescope.
Fun to hear you used this software already long time ago.
I added my attempt to fit a 3" Wynne coma corrector on my design 12" f/4 Newton.
http://astrofriend.eu/astronomy/proj...ton-v1_03.html
Today I have started to learn how to use OSLO (optic design tool). Looks to be a lot of information about how to use it. After a day of struggle I have a Newton on the OSLO screen.
/Lars