Part of render blurry I am trying to render a scene but as you can see in the image, the lower part of the shield (the line between red and white) is blurry. I've tried changing dof and tweaking materials but the problem still persists. What should I do? 
Blend file
Move your empty closer to the camera and lower the aperture value, real world cameras also have approximately one third of DOF close and two third far from lenses.