I've been shooting with my 5DII for a year now after upgrading from a Rebel XTI (5 years with that). With the Rebel, I always hated the noise when I went above 400 ISO so I always shot in 100-200. With my 5DII I notice I'm doing the same and I hesitate to shoot above 400 sometime especially in lowlight situation being afraid of noise or the loss of dynamic range. Is it wrong to be afraid of shooting higher than 600 ISO? Are there any other Photog out there that hesitate to shoot above 600 ISO on the 5D line up?