Joe, I don't really know your camera, so I can only speculate. Can you remove one of the filters and take luminance data only? Can you use the camera without a filter? Perhaps you can get a matching clear filter for the set and replace (temporarily) one of your color filters. You should contact SBIG and ask them directly. My camera has 5 filter slots on the filter wheel (an SBIG CFW8), so I can use a clear, red, green, blue, and Ha filter for any exposure, without changing out a filter. The wheel simply rotates the selected filter into place. I spend most of my time imaging with the clear filter, and add a little color data at the end of a session. The human eye is not really all that sensitive to the color data, so it doesn't need to be as smooth and detailed as the luminance data. If you saw my typical RGB data before luminance is layered over the top, you would break into laughter... it is usually pretty bad! The luminance is the place to spend your time and effort.... then add a little color you have arrived!! Cheers, Tyler -----Original Message----- From: utah-astronomy-bounces+tylerallred=earthlink.net@mailman.xmission.com [mailto:utah-astronomy-bounces+tylerallred=earthlink.net@mailman.xmission.co m] On Behalf Of Joe Bauman Sent: Sunday, May 22, 2005 6:23 PM To: Utah Astronomy Subject: RE: [Utah-astronomy] New Image Posted - M106 and Friends My SBIG has three color filters. I understand about averaging and stacking. But how do I get a luminance exposure (or a series of them like you did) without using one of the color filters? Sorry to bug you -- Joe _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com