Let me expand: A couple of years ago, someone showed me an article about people who have an extra color-perception chromasome (Rich, was that you, or was it in Patrick's "news"?). It seems that these fortunate folks can see colors that the rest of us cannot. Their vision is otherwise normal, but their "rainbow" contains many more colors than ROYGBIV. I think this is somehow connected with Brent's ability to see detail without filters that others apparently require a filter to see. I see this "experiment" as more of a physiological excercise than an equipment trial, which is why I downplay the hardware aspect. Having a large sample of filters and telescopes is what you need for a product comparison, or application trials, but not for the test we are talking about. "Filter Seminar" is a term best applied to this second activity, and that is the one that should be open to everyone, but not the visual tests. Chuck __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com