Object Motion Blur

Object motion blur applies a blur effect to make fast-moving objects appear to move more smoothly in animations. It is a form of "temporal antialiasing."

Left: Object motion blur. Right: Object motion blur with dithering.

Don't use object motion blur to simulate the blur created by a camera. For this purpose, use image motion blur or scene motion blur.

Applying object motion blur is a two-step process:

Turn on object motion blur for the object you want to blur, using the Object Properties dialog.
You cannot apply both image motion blur and object motion blur to the same object in the same rendering.
Before you render, turn on object motion blur in the Default Scanline A-Buffer rollout of the Render Scene dialog.

Object motion blur works by rendering multiple copies of the object in between frames and then rendering them together. It is not affected by camera movement.