In this Blender 2.7 Tutorial #45 I cover:

-How to set up a 3D scene and camera that will best show depth-of-field blur.
-How to create depth-of-field blur (“bokeh”) in your Blender render, focusing on a target object.
-A little bit of photography theory: the affect of a camera’s aperture setting on the end result of a photograph
-How to get a “tilt shift” effect on large scenes by faking the size of the virtual camera.
-NEW to 2.74!: How to show Depth of Field blur in the 3D Viewport.

Visit my Blender 2.7 Tutorial Series playlist for more Blender Tutorials: