DSLR Ha image processing - flats and channels

[troypiggo]

Was doing some testing last night and thought I'd try some Ha imaging as well. I was using a 6nm Ha EOS Clip filter in my 40D. Bit too narrow, 13nm on the way. Of course, now I have questions for you as I try to process them.

The light frames are predominantly red of course, but there does appear to be a little blue and green in there. I'm sure I've read somewhere that you just take the information out of the R channel, and can discard the G and B as they'll likely just contain more noise. Correct?

The flats. I was testing out a lightbox setup as well. Flats should be taken at the same focus and with the same imaging train as the lights. So I didn't want to take off the camera and remove the filter. I took the flats with filter in place, so the flats also turned out predominantly red. Does this cause problems? I believe that the stacking software (I'm using Nebulosity) handles all the channels itself anyway.

So do you image your flats with filters in place too? Or should I have removed it?

Any good links to DSLR narrowband image processing? I've seen a couple, but nothing is really giving me the nuts and bolts that I want.

[multiweb]

You do your calibration and flat fielding prior to debayering. That's the first thing you should do. Then you separate the channels. Of course you shoot your flats in the exact same conditions you shot your lights in. Same filters, focus, camera orientation, etc..

[Terry B]

I can't comment about the processing as I don't know but all flats shoud be taken through the respective filters.
If you use 4 filters then it is probably best to do flats throught each filter separately especially if the filter is close to the imaging chip. Dust motes etc will be more prominent with a close filter.

[troypiggo]

Thanks guys, as I thought.

Still interested in links/tutorials etc.