A very few copies of the 5D2 exhibited a hardware fault (unbalanced A/D channels). I saw and analyzed raw files of four of such cameras; all have been repaired by Canon in the meantime.
See the thread https://photography-on-the.net/forum/showthread.php?t=674155
It appears now, that this kind of fault is present in the 7Ds as well. There are not many raw files around yet, but most of those I analyzed exhibit this fault to different degree; some are probably negligable, while others look worse.
The fault is visible in low-ISO raw images, only in the very shadows. As usual, some posters will say that a Canon camera is not supposed to be defamed by underexposed shots. Those, who believe that the 7D should reproduce details in the deep shadows as well, may be more interested on this issue.
The fault can be shown the easiest on ISO 100 black frame shots. A black frame shot looks normally pretty boring. Example: from the 50D, ISO 200, first the composite color, then the single raw channels (only one of the greens):
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Now, let's see the black frame of the 7D, with ISO 100:
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The raw files can be analyzed by Rawnalyze, see
http://www.cryptobola.com/PhotoBola/Rawnalyze.htm
If someone uploads such raw file(s), I can do that too. It would be interesting to find out, how much this fault affects the converted images. Unfortunately there are not many samples out there with low ISO and very dark patches.
) and have a look at it to see if the problem is repeatable on a different 7D body.
