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Chris. Thats the killer with Ha, the time available to image, projects dont just stop when the moon appears.
Marcus. It took longer for me initially working out the best iso/exposure times etc. After that, it was the need to make more darks if the temp changed (Ive used the same library for a year on the CCD), the more subs required at a max of 10min ea (the CCD has 80% QE, and I can take far longer subs with it, for overall less exposure time), difficulty in composing without removing the Ha filter 1st, I needed 2-5min subs to see the image to compose, on the CCD I just flick to the Lum filter and bin 3 for continouse 5-20sec exposures to allow fine composure tweaking.
RGB is sort of quicker on the 40d, but given the lower QE, you need more subs, although for bright objects the 40D would win with acceptable results.
And handling large numbers of huge subs took much longer to process (the CCD is only 3.2 mpx). PS was slow too with the huge images. I reduced them 1st in the end, but that kind of lost the res advantage of the 40D (not that it mattered much at long FL).
IP did a great job without trouble processing from disk, but I prefer CCD stacks interface, more contol you can see. CCD stack just died tring to us it with the 40D subs, id need a much faster PC and huge ram to make it sing with the 40D subs.
The CCD allows very fast autofocus on my rig, although the live view on the 40D is magic and also fast, but manual, and I needed to slew to a bright star to focus through the Ha filter (which works well BTW), so the 40D takes longer to focus given its manual and the need to slew to a bright star.
Frank, yep, Ha is an essential tool IMO, use it all the time on Nebs, no good for galaxies though (ie broadband scources).
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