I mentioned that in my reply in the original thread, Erik. Older refractors were corrected for different lines. On Fri, Jan 2, 2009 at 10:24 AM, <zaurak@digis.net> wrote:
Lets also not forget the color correction of various lenses. With my f5, I am hesitant to describe lilac or bluish tint, filters help but there is a big difference compared to apcohromatic refractors. I know what you will say, get a reflector or cassegrain. Seeing airy disks is very pleasurable and makes the acohromat very worhtwhile Brightness also is factor, ie the brighter the object the more purple halo you have. An apodizing mask is also helpful.
I think Kirk is correct that society in general has gotten color illiterate. I have found some pretty profound differences in the way Webb, Smyth, and Haas describe the colors this indicates to me that perception does vary among very experienced observers. I do find myself agreeing with Smyth and Webb more than Haas. Perhaps as Chuck said the difference between male and female.
Erik