I've noticed the same phenomena while viewing prominences with my 40 mm hydrogen alpha filter. At first only the most intense flares are visible, but the longer I observe, the more detail becomes apparent and smaller and fainter features become visible. I don't believe it's seeing. It seems to be a function of time. The longer you observe, the more detail you get. Probably psychological as the mind begins to ignore the overall view and search for aberrations in the field. Jeff Vandecar -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.