Originally Posted by
Donald
John
None whatsoever. You can have as many as you can cram into the image. One of the things to try and learn (I used Nik's own video tutorials), is when to use single control points to cover a large area and when to take the size down and have lots of small points covering the same area. You can get dramatically different effects depending on how you use the control points. I'm still not sure I have mastered all the subtleties.
For example, in my image above, there are two control points in the sky that, between them, cover the whole sky. But then overlaying them in some areas in the sky (as can be seen), there are more control points that then adjust (or block) the effects created by the larger control points. So, the options are limitless. An amazing tool.