I made a threshold node which generates a black & white image based on a threshold value. Moreover the edge between the color can be softened by a smooth parameter.
I agree that a similar effect can be achieved using an RGB Curve and a Color ramp, but this is a lot of pain. I use this effect very often and it is very convenient to have such a node.
I would like to know what you think about the threshold node, in particular if you think it’s useful enough to be integrated in Blender.
Here are 2 images of the node in action.