The question is very simple, and it surprises me I couldn't readily find the solution by googling: I want to reduce the depth of field of a photo in Photoshop. I expected to find something that allows to convert the sharpness of any given area to a smooth mask, so that I can then play with the curves of that mask... but nothing. I only found a "focus peaking" action that uses the high pass filter (very poorly) and tutorials on how to select the foreground image with the lasso -__-'''
What I was hoping for is something that allows me to smoothly simulate a real f/2.8 when the picture was shot at f/5.6. Which means that a binary selection (in focus/out of focus) is no good; I need a smooth mask that allows me to multiply the already existing blur.