When developing CR2 files in ACR (version 8.4), I get almost always terrible artifacts into the picture, particularly in darker shots (night, thunderstorms), which can not be completely removed in Photoshop. These show up mainly in gradients (such as sky after sunset), even if I change only a little of the settings.
With identical shots from NEF files (because sometimes two different cameras are used at the same time) this color breaks in ACR are not given.
Why might that be?
Which Camera Profiles are you using for each camera? Have you tried different ones?
Can you provide a screenshot of what you’re seeing?