Playing with Stephen's DC-3 shot, I wondered why turning crop on/off was also affecting colour. He comments:
"Control points must reference their position by x,y co-ordinates in the frame. If that frame is changed i.e. cropped then the position of a control point changes and has an undesired effect. I have noticed this in all versions of NX with all types of control points. From the edit list you should see the neutral control point is one of the last entries and crop one of the first. When you remove the crop notice the control point move."

If his theory is right, one needs to be a bit careful about peppering control points when intending to crop??

http://www.worldphotographyforum.com...1&d=1196511794