Shortly after the Canon EOS 5D Mark II shipped, users began reporting a strange "black dot" error, where small points of light were rendered with an accompanying black dot just to the right. We didn't see the phenomena until we took a special photo to demonstrate the issue. It took several lighting, lens, and ISO changes to get a shot that showed the effect. Note that these elements are very small in the frame, and you are unlikely to see them except when the image is enlarged significantly.

Before 1/60 sec, f/8.0, ISO 3,200, 24mm Enlarged 400% Firmware 1.0.6	After 1/60 sec, f/8.0, ISO 3,200, 24mm Enlarged 400% Firmware 1.0.7

In December of 2008, Canon announced that they were aware of the problem and working on a fix, and on January 7, 2009, they released a firmware update to address the problem. Above you see the before and after shots, taken from the same location with all the same settings.

A banding issue related to the sRAW1 format was also fixed with the firmware update, but we do not have before and after shots for that. We'll be reshooting some of our test shots with the new firmware to see if anything else might have changed, so stay tuned.