400D is no good for deep sky imaging, at least worse than 300D/350D, so unless Canon comes out with a 6M entry level model again, not much chance that I shall go for one. Second hand 300D/350D is not very good, as the shutter count is very high usually, making them very failure prone.
With the recent success of the DMK cooling experiment, maybe going for a color version DBK is good choice, first of all, cooling is proven to be effective even up to 5 minutes exposure, and stacking would be very easy for camera like this, the larger pixel of the 1/4" version is also better, of course, with smaller field of view than a 1/3" version but also cheaper.
C mount lens is also cheaper than Canon L prime lenses, which makes thing even more economical. the 1/4" model of the DBK is just the price of a 2nd hand 300D/350D. Of course, pixel count is far less, and the imaging area is far smaller too, but even astronomical cooled CCD is of similar pixel count.
The major problem is then, it's not very portable since a PC has to be used, but when autoguiding is placed into the equation, it becomes less an issue. Snapshot type imaging is an exception, however.
- a 400D for casual snapshot and deep sky
- DBK is also for casual deep sky, but no snapshot
Maybe I really need both?