Using Multi-Pass Rendering Effects

Create panel > Cameras > Target button or Free button > Parameters rollout > Multi-Pass Effect group

Multi-pass rendering effects use multiple renderings of the same frame, with slight camera movement between each rendering. The multiple passes simulate the blurring that film in a camera would register under certain conditions.Autodesk VIZ provides a single multi-pass effect:

Tip: This effect is for the default scanline renderer. The mental ray renderer has its own depth-of-field effect. See Depth of Field with the mental ray Renderer.