I have seen many tutorials on NX, the latest being Vincent Versace's. In them they deal a lot with landscape examples; I shoot birds. My questions has to do with white and black control points. I can't see why I would want to use them - but in all tutorials they do??? I took an image of a gbh in a tree. I open it up in NX and click the double threshold box. There are some black areas and no white areas. I move the right slider to 253 and see 1 tiny area of white. When I select the black and white control points in that area, I get much more black and white areas. Why would I want to do that? Are there others who just ignore b and w points?