Now i am experienceing hi level and low level horizontal banding in all of my photographs (most noticeable in shadow areas) even it 100 ISO and with varied lenses. (16-35, 50mm1.4, 24-70).[a href=\"index.php?act=findpost&pid=104374\"][{POST_SNAPBACK}][/a]
If it has gotten worse, and you are doing everything the same, then it is probably a malfunction of some sort (a small amount of banding exists in just about all DSLRs, often more visible at high ISOs on Canons because of the low 2D rando noise).
Besides the camera, Radio interference and a faulty flash could be the problem, as well. Sometime specific lenses make noise when focusing, but you have to have the camera set in suvch a way that focusing can occur immediately after exposure for it to be an issue.