Hi Michael, We have read up on dark frames and noticed how to use them in DSS but haven't given them a try yet. We'll make this one of our next experiments with the camera and see how it goes. We remembered after our last post another issue we encountered when we increased the ISO was we could take pictures in the backyard like it was daylight. We only need a single cloud in the sky for the light pollution to reflect off it like a giant diffused lighting system. The good news is we don't need any outside lights at our place.
So it takes a while to get a time with no moon and no clouds like it happened the other morning. Thanks for your tips.
Clare & Peter