These issues have been raised on EOS forum plus elsewhere including Rob Galbraith
From The Canon site -
Link =
http://www.canon-europe.com/Support/Consumer_Products/products/cameras/Digital_SLR/EOS_5D_Mark_II.aspx?type=important&faqtcmuri=tcm:13-618473FAQ: Important information for EOS 5D Mark II users.
We have learned that some users of the Canon EOS 5D Mark II digital SLR camera have identified two types of image quality phenomena that appear under certain shooting conditions.
1.
“Black dot” phenomenon (the right side of point light sources becomes black)
2.
Vertical banding noise
Cause
We are currently investigating and analysing the causes, and examining measures to reduce or eliminate these phenomena by providing correction firmware. An announcement will be made on
www.canon-europe.com as soon as measures have been determined.
Answer:
Details of the phenomena and shooting conditions under which they are likely to occur are as follows.
1.
“Black dot” phenomenon (the right side of point light sources becomes black)
When shooting night scenes, the right side of point light sources (such as lights from building windows) may become black. The phenomenon may become visible if the images are enlarged to 100% or above on a monitor or if extremely large prints of the images are made.
2.
Vertical banding noise
If the recording format is set to sRAW1, vertical banding noise may become visible depending on the camera settings, subject, and background.
▪ Vertical banding noise is not noticeable if the recording format is set to sRAW2.
▪ Vertical banding noise does not occur if the recording format is set to RAW or JPEG.
▪ Noise can be reduced if C.Fn II-3: Highlight tone priority is set to 0: Disable.
Canon apologizes for any inconvenience caused and thanks photographers for their patience.
