While processing a images from this past weekend taken with the 5D Mark III... Images taken at high ISO (6400 and 12,800) with no noise reduction show a very clear criss-cross pattern across the image faintly. Once you apply about 20 on the NR slider, it will go away. I do not see this with the in-camera JPEG's or with Canon's DPP software with no NR applied to the RAW files. Is this a known issue that will be corrected for the final release of 4.1?
Here is a crop showing this happening. It is not limited to just dark or light parts of the image, but the entire thing.
Yeah, I suspected that might be it. I've seen this happen with noisy images with lens corrections before, but it is rare. I've never been able to recreate it myself, but I've seen it happen to others.
Do you think you might submit a bug report to Adobe, or perhaps send a PM to Eric Chan to provide your RAW file to them? I'm not sure they've ever investigated this problem thoroughly. It is a real problem when it happens on Micro-four-thirds cameras where you can't turn off lens corrections (they happen automatically and can't be disabled) and it would be great if Adobe could track down what exactly is causing it.
I believe with previous problems people reported them here:
However, if you don't want to deal with that you could always PM Eric Chan. This is people page here:
Just click on the "Send Private Message" link under "Actions" on the right and point him at this thread. He can probably pretty quickly tell you if your RAW file will help them out or not.
This is not considered a bug, as far as I know. You do need to apply at least 20 NR anyway.