Great explanation, Tyler, many thanks. I'll take a look at test exposures first to see if I'm maxing out stars. You are certainly right about the learning curve. At least when you set up, you don't have to lift something weighing 74 pounds onto your tripod -- I hope! When I bought my SBIG I should have spent more and purchased one with a self-guider built in. It would have saved a great deal of trouble. As it is, I need to line up on north, level my tripod, and then go through the onerous ordeal of fiddling with collimation, before I start to image. To make a good photo I need to stack views. Until now I have been limited to exposures of three minutes or so because the telescope doesn't track well enough to allow longer images. But finally I think I will get the connections right to use my Meade Deep Sky Imager as a guider, connected to a refractor on top of the 12". Maybe I can get some interesting views also. Best wishes, Joe