Trapcode Particular
Depth of Field (DOF) simulates the focus of a real camera. Depth of Field is useful for increasing the a scene's realism as well as matching your Particular effect to footage shot with a real camera where Depth of Field is apparent.
By default, DOF is turned on with the Camera Settings option. Choose the Off option to turn off DOF.
Depth of Field set to Off (left) and Camera Settings (On) (right).
This control sets the kind of render provided by Depth of Field. This setting only affects Sprites and is disabled for other Particle Types. There are two Depth of Field Types.