I always wonder which is better for a 6" achromat, to use an anti-fringe (violet) filter versus stopping down the scope for better viewing? Would appreciate any thoughts or results of actual experience.
Anti-fringe filter vs stopping down an achromat
Started by saiedmabrouk, 05/07/2010 08:15PM
Posted 05/07/2010 08:15PM
Opening Post
Posted 05/08/2010 03:51AM
| Edited 05/08/2010 03:54AM
#1
What has been Your experience? Or do you ask because you have no filter to trial & compare? With a 6" f/8 reflector, I found that full aperture despite a turned-down edge revealed much more lunar & planetary detail not to mention deep sky light grasp than when stopped to 5" (eliminating the turned edge effect). I preferred a degraded 6" to a perfect 5". IOW aperture trumps all else, so if you have no filter, get one. Or two or three, other colors are also effective (such as Yellow or Orange). Colored celephane or photographic gelatin filters cut & mounted in slide frames are inexpensive & may be hand held between eye & eyepiece. I find no good reason to stop down my 80mm achromat refractor & the turned edge of the 6" reflector has been corrected.
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