Cool!  I was unaware of that!  I know it's a great camera, I've been very happy with it.  I was using my SL1 for my prev comet pix for no particular reason, didn't know what lens I was going to need and opted for the longer focal length side.  I probably should've switched, but once we started getting results the thought never occurred. Very nice to know that it's great for astro!  Now that you've turned me on to processing flats, I'll have to play with it some more come winter.