I had an ACF conversion done on a 14" and just received it on Tuesday. I got it up on the mount but wildfire smoke was so intense Tues night I didn't get much of a test run, Vega barely showed, it focused fine, and I was very impressed with the amount of image shift during focusing..very little, even at 250x Vega was barely moving when I reversed direction. Boy will that make planetary imaging better!
Anyhow, yesterday we had a weather change and the smoke was gone last night, so I got to wring things out a bit. It does appear superior overall visually to the Schmidt configuration of my other 14" which I swapped off the mount...focus is easier, the image 'snaps' a little when it's close something I never had with the other one (that one was fine once you nailed it but finding the 'nailed' point was subtle). Stars are much better pinpoints and easier to get there.
What I don't know about is this...bright stars like Vega show a very crisp, narrow ring around them. With my 14mm Meade series 5000 80 degree eyepiece (253x, 0.3 deg TFOV) , the ring is about 80% of the field wide. I think the ring expands and thins as I hit focus, but I'll have to recheck that.
It was also detectable on alignment stars like Alpheratz.
I don't recall ever seeing this on the other 14 with the schmidt style optics.
I looked at M13, M92, some other cluster type targets and the ease of focus and pinpoint stars are great...but the ring has me worried.
Edited by MtnGoat, 31 August 2017 - 01:06 PM.