Best Planetary 4" refractor?

Started by T.R., 05/10/2006 01:19PM
Posted 05/10/2006 01:19PM Opening Post
Forgive me...I did a forum search but I couldn't find this direct topic anywhere. Opinions please on the best 4" Apo for planetary viewing. Visual only, binoviewer. To me there would be a difference in the non-baffled short focal ratio TV's vs. the fully baffled longer focus Tak's, SV's for the finest planetary details. Support your choice with examples/comparisons please, thank you in advance.
Posted 05/10/2006 06:39PM #1
Tele Vue's TV102 is f/8.6

Ron
Posted 05/10/2006 07:55PM #2
APM makes a mighty fine APO from the
TMB 100 F8 triplet. I believe the TV102 is a doublet.
Posted 05/11/2006 02:24AM | Edited 05/11/2006 02:25AM #3
Nikon 4" F/12, Showa 4" F/10 and Takahashi FC-100N F/10. All are hard to locate and the Nikon is very expensive.
Posted 05/11/2006 04:06AM #4
You say the doublets give better contrast than the triplets? Don't the doublets have more CA? Would this not make for worse contrast?

I understand that the more surfaces you have, the worse the contrast, but doesn't CA complicate the analysis?
Posted 05/11/2006 03:10PM #5
Every scope regardless of aperture will show something when it comes to planets, if you expect some serious detail the minimum aperture for a refractor is 5", the 4" simply does not have the resolution needed for the "finest planetary detil", and will run out of light at higher powers when combined with a binoviewer.

Thanks,
Vahe