I found out today that using AstroArt 3.0 you can do long exposure images with UNmodified webcams ! (not tested it on the scope but works fine in the 'lab')
How? or are they doing off-chip integrations?
I presume so. Would be interesting to try at the scope as an experiment I suppose. The problem is there is a lot of noise generated by webcams and after doing some experiments indoors with 10 and 30 second exposures a load of vertical lines appear, but these could be made into a bias frame and subtracted easily enough.
I would not worry about that because you would not use 20-30 seconds for guiding because you may at that point already have PEC problems, most guiding is done at about 1-5 second images.
I was just talking about using the webcam for long exposure imaging, not guiding - for anyone that doesn't have a long exposure camera, but has a webcam.