Mon 17-Aug-09 06:32 AM | edited Mon 17-Aug-09 06:33 AM by MotoMannequin
The D40 is an excellent camera, and for your purpose, probably either D40 or D5K would be fine. I agree it probably isn't a worthwhile upgrade for your stated purpose.
Regarding the issue of noise, similar issues were hotly discussed over a year ago, comparing D300 to D50 (again a 12MP camera compared to 6MP camera). In casual snaps, the D50 looked superior, but when we actually got down to doing well-controlled tests, the D300 won by a large margin. You can probably dig up the old threads in the D300 forum if you like.
If you were shooting with ADL on, then that explains the poor shadow noise performance. ADL underexposes the image to protect highlights, then applies d-lighting to raise shadows in post processing. If you do this in any camera, you've got a recipe for shadow noise, and that's precisely the effect. This may be a contentious statement, but I don't find ADL useful for anything but casual snapshots.