Many video effects plug-ins including Lenscare, Flair, Fresh Curves, and Taronites Zborn Toy for AE, OFX and Photoshop.
Lenscare moves depth of field and out of focus generation to post production. If you need high quality camera blurs with the flexibility of 2d post processing, Lenscare is a great choice. It can get you rid of long extra 3d rendering times. The key aspect during the development of these filters was to match the real thing as good as possible. Lenscare is available as plugins for Adobe After Effects and Photoshop compatible programs.
Depth of field effects (dof) happen in all real optical devices to a certain extent. It is heavily used in photography and film as a style element. In computer graphics dof is usually generated using ray tracing techniques which increase rendering times considerably. The depth of field plugin generates those fast as a post process. It needs a depth buffer for its calculations.