Any sample photos for the reported problem?
BTW, CMOS has the problems of random noise because of the hardware per pixel (photo transistors, amplifers, etc.) can never be made to be identical, whereas CCD has the problem of inconsistency line output and fading along the line (chain of a series of waveform) and thus more susceptible to bandings.
All in all, each of them has the inherit problem of its own. So, it all depends how proper measure(s) plus accurate calibration are made to the camera for its design and in the factory, respectively.
For the 5D, it is just an entry level FF DSLR from Canon, just like the 400D of the 1.6X APS-C lineup. So, it will be of not big surprise if it cannot meet the performance and reliability of the EOS 1 series cameras.
Originally posted by benjikan Just Copied this from e Photozine. It seems that the apparent problem with the K10D is not exclusive to PENTAX:
Hi, I have had terrible problems with chronic lining/banding appearing on images across all isos.
I sent my camera back to Canon U.K. 3 tmes each time coming back with same problem. Tried different lenes, flash cards etc but no improvement.
As a result I borrowed a camera from my local canon agent in Ireland, tested it, straight away same problem. Only constant between my camera and this one was flash. So rented a 580ex, to go shoot wedding, same problem in the church, I was fit to scream!
I would rate 5d as an unusable camera for the professional. Also Canon U.K. and Canon U.S.A did not appear to know about this problem. I like others had to find out about it on internet. This is a terrible camera and atrocious customer support from canon.
In short I have noticed this problem across various isos starting at 100, with different lenses, memory cards and flashes but indoor shots in mixed light very susceptible to this banding.
The shop I bought it from, B&H Photovideo, would not entertain replacement or refund even though camera was sold in this state and I have repair record to show this. In fact customer service agents very unhelpful there, to the point of rudeness.
What are we poor saps who shelled out a fair whack of cash on these rubbish cameras to do?
see this link for other people who had same issue
DSLR Photography » Chuck Westfall comments on 5D camera banding issues