Quote:
Originally Posted by Slawomir
True, nonetheless I had noticeably but not vastly larger halos with my ED doublet than with the current triplet (same user :-), camera, same 3nm n LRGB filters, location, aperture and similar f-ratio). So I suspect an achromat would give inferior RGB/narrowband data relative to an ED doublet at same f-ratio, not to mention a well corrected triplet  |
Interesting comparison, Suavi.