Victor, It appears you are into solar astronomy. I have seen some pretty impressive images taken with telescopes around 100mm aperture in H-Alpha. It makes me want to go out and buy one, but I am wondering what one can do, except oogle and take pretty pictures. Is there anything of a scientific nature that an amateur can do, other than submitting such images to a database, if one exists, for the pros to look at? Stan -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.