Reply to thread

I think you are seeing the clipping indication.  You can turn it off by clicking on the triangles in the top corners of the histogram in ACR, or you can reduce the exposure, Highlights, or whites sliders so that the image no longer clips.  You'll often find that the background is causing the problem because the camera has tried to expose for the foreground objects which tend to fill the image's middle ground.  CS6 had a nice vignette tool, but CC as a _really_ good tool called Radial Filter  (j)  Make sure it is set 'Outside' and lower the exposure or Highlights sliders to reduce over exposed backgrounds.

BTW  I never have the clipping enabled in ACR because you can see what is happening from the histogram and the afore mentioned triangles in the ACR histogram.