I think I have a clue as to why there are black pixels appearing next to extremely highlights in 5D2 photographs. Just to see if my photographs had the same problem, I pulled up a night-time image in DPP with lots bright lights...and sure enough there were the black pixels near the extreme highlights.

I stared at the computer screen trying to figure out what to do and then suddenly, without doing anything, they vanished...literally. Here is what I think is happening, (and I was able to duplicate this); the problem is with DPP and not the camera. For some reason DPP is still crunching away at the large 21.1. MP image and doing something to the image that produces those black pixels, and then after a few more moments of doing nothing they go away. I looked at several images to see if this was the case, and it occurred repeatedly.

Then I opened an image that previously exhibited those black pixels, confirmed they were still there, and then quickly converted it to a TIFF file and saved it. Those black pixels were immortalized onto the TIFF image.

So, DPP is doing something to the image that either (1) causes the black pixels to appear and then removes them, OR (2) the image is taken with the black pixels and DPP is instructed to remove them automatically.

What I don't know is if the black pixels reappear when performing adjustments to an image in DPP or if they don't disappear when using another RAW converter. I would be interested to know if others are able to confirm this with their own 5D2 images and DPP, and other RAW processors.

Johnny

http://www.flickr.com/photos/latitudes/