ZFocus blurs objects based on their distance from the camera, using the ZBuffer information from the scene. You can use Zfocus to create effects such as foreground elements in focus and background elements out of focus, similar to a camera shot using a high F-Stop setting.
The Zfocus dialog box has two sections. On the left side of the dialog box, you select what and where the Zfocus affect is applied. On the right side of the dialog box, you specify how the Zfocus effect is applied to the scene.
Preview: Lets you quickly preview the Zfocus effect.
Scene Blur: Applies the blurring effect to the entire scene, not just a portion of it.
Radial Blur: Applies the blurring effect to the entire scene in a radial fashion, starting at the center of the frame. This is useful for emphasizing fish-eye lens effects and effects where the edges of the frame are blurred. This type of Zfocus depends on the Focal Range and Limit settings.
Focal Object: Lets you set Zfocus to work with a specific object in the scene. The selected object remains in focus, while objects at greater and lesser distances from the camera are blurred. This type of Zfocus depends on the Focal Range and Limit settings.
Select: Lets you select the object to use as the focal object. Only one object may be used as a focal object per Zfocus entry in the video post queue.
Affect Alpha: When this option is active, the blur effect is also applied to the Alpha channel of the image when you render to a 32 bit format. To composite the blurred image over the top of another, enable this option.
Horiz. Focal Loss: Specifies the amount of blur applied to the image in the horizontal direction. Valid values are from 0 to 100% focal loss.
Lock: Locks the horizontal and vertical loss settings together. When active, if you change horizontal, the vertical is automatically updated to match.
Vert. Focal Loss: Specifies the amount of blur applied to the image in the vertical direction. Valid values are from 0 to 100% focal loss.
Focal Range: Specifies how far away from the center of the image (Radial Blur) or from the camera (Scene and Focal Object) the blur effect begins. Larger values move the effect farther away from the camera or the center of the image.
Focal Limit: Specifies the outer limit of the blur effect. Set a high limit with a low range to get a slight variation over the amount of blur in the scene. If Limit and Range are set close together, the amount of change in the blur effect is greater over shorter distances.