So, I'm using depth of field with hair render with a unique problem. The hair directly in front of the object look fine and the hairs to the side and back blur. Its not the camera settings, rear or front blur distance. The distances are correct, and I can gauge this by other objects in the picture to the left and right. I have attached another picture I was goofing around with that has done the same thing. Any suggestions?
Hair doesn't seem to play well with the DOF effect. I would suggest that you use one of the "generate" options in the hair object (other than none) if you want to combine the two. Unfortunately you'll then lose the standard hair shading, but there's a geometry hair shader that works okay.