Quote:
Originally Posted by ghsmith45
Should be ok as long as you refocus for each filter.
Geoff
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Long time ago I had an Orion ED80 so a doublet. Very neat optics. Narrowband was great. RGB with an OSC wasn't so good. Blues were pretty out of focus when red was in focus and green close to focus.
For this reason I bought an APO triplet. That sorted it out. Everything was sharp and in focus. As Geoff said, you need to refocus for each filter if you use a mono camera. I'd also venture to say that LUM will still be more bloated with a doublet because LUM contains all the colors so it's logical to assume an APO would give you a sharper LUM?
