Yeah Sam, I read that. Evidently you missed the fact that that isn't enough explanation or I wouldn't have asked for details. I can already "paint onto the image the Gaussian blur effect in just the areas that I want in a very controlled manner creating reduced depth of focus and separating the main point of interest from the background" using the Gaussian Blur. So I assumed there must be a more indepth reason to redo it using the History Brush.