Quote:
Originally Posted by kosborn
Thanks for the advice guys. I do have a cheapo 1.25" Barlow that was thrown in for free when I bought the Esprit. I might have a 1.25" - 2" adapter somewhere so will give it a try. I was definitely thinking deep sky so 1900mm focal length at f/7.5 would probably be good.
Another question though. Would I need to leave the coma corrector in place or should I leave it out. Accurate back focus distance might be difficult with coma corrector, Barlow and adapter. I'm guessing that off-axis coma is less of an issue with the longer focal length and smaller field of view?
Kevin
|
At f7.5, most commercial coma correctors designed for f3.5-f5 will over correct. Yes leave it out especially if you have a smaller sensor, ie APS C or smaller.