Thanks Rod and Rex - a question without notice... As I haven't ever attempted to have a second imaging session and add it to the original, I take it I would subtract the new set of darks from the new set of lights and then stack these light frames with the original light frames? I would also use Align and rotate as the camera alignment will no doubt be different. I know that Backyard EOS has a function to line up subsequent shots but the camera I am using for this doesn't play with BYEOS (300D). Any suggestions or guidance will be gratefully accepted.
Bruce.