The problem is that the integrated image aligned on the stars results in a fairly bad comet smear since at longer focus there is much more movement of the comet during a 1 hour total integration time. I have no idea how to get rid of this artifact as it covers almost an entire quadrant of the image. So I need to figure out how to prepare a background star image to be used in this particular case where there is excessive comet motion at longer focus.
Thanks
Dave
