Isn't it possible to run Windows programs on the Mac? If so, you may want to consider Registar. You may also stack images with Photoshop, but it is tedious if you are stacking a lot of images. Scott R. Scott Ireland ireland@gate.net www.rsiphotos.com _______________________________________________ Astro-Photo mailing list Astro-Photo@seds.org http://seds.org/mailman/listinfo/astro-photo