Hey, that might work. I will rush home tongigh and give it a try! THANKS. Chris --- Brian Skiff <bas@xxxxxxxxxx> wrote: > >> ...I would need of course a red filter > >> that excludes hydrogen alpha. > > Not true. See any of the large number of > papers in the > professional literature that obtain H-alpha images > just in the > manner I described. The problem is that the H-alpha > filter is > not so narrow that it excludes the red continuum. > So you subtract > out of the H-alpha image some fraction of the flux > using the > broadband red image. > > \Brian > -- > See message header for info on list archives or > unsubscribing, and please > send personal replies to the author, not the list. > > Take Care, Chris Astro: http://www.schursastrophotography.com Robotics: http://www.schursastrophotography.com/roboticsmain.html ____________________________________________________________________________________ Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.