The lens flare caused by a bloom is still a lens flare. It sounds to me like you're describing two different effects, and using the same name for them. I think that the "hot spot" effect that you are describing is known as a bloom, and the reason that they can generate lens flares is that as far as a camera is concerned, it IS a light source. All it sees is photons, after all :) This does not address the initial post however, which is what my first reply was intended for. That described a different goal from what your suggestion is a solution for.