DBE

[sreilly]

As I get more use to PI and the DBE process I decided to try an experiment in which I wanted to image a nebula with the Moon present and see how effectively DBE could handle the gradients. What I noticed first is that some imperfections in my flats seem to become prominent when the Moon is bright. I can't qualify that more than comparing images taken when the Moon was not present vs last night and tonight's where the Moon is nearly full. I'll take new sky flats tomorrow if the sky is clear and compare to be sure. Has anyone tried LRGB imaging when the Moon is present and gotten good results removing the gradients with DBE? I suspect that the brighter nebula will probably show less gradients just due to the overall brightness of the nebula especially if it covers most of the CCD chip. Maybe I should have picked a dim galaxy for this but I had already started a nebula project and the way the Summer's been, most of my clear nights seem to have Moon in them! And then of course it's been to hot to fish as well!

[Nocturnal]

Steve,

this will work but remember that DBE only removes the estimated signal and leaves the noise behind. The larger the signal (the brighter the LP or moon) the more noise there is. So be prepared for a more noisy image compared to when there's no moon.

[sreilly]

Understand the noise Sander but I'm thinking that if enough data is taken to suppress the noise and this data is combined with data taken under better conditions, no Moon, that it should add to the already better data (no Moon). At least that's my thought.