The Z-Depth render element allows you to extract information about how far a point is from the camera. This information can be later used to add post production effects like depth of field.
Name - the name of the render channel
Black Distance - in a Z-depth element a black distance is the distance closest to the camera. This parameter allows you to specify how far from the camera the z-depth element starts.
White Distance - in a Z-depth element a white distance is the distance farthest away from the camera. This parameter allows you to specify how far from the camera the z-depth element ends.
Depth From Camera -when enabled the Black Distance and White Distance are taken from the far and near clipping plane of the camera
Depth Clamp - allows you to enable or disable the the sampling of the current render channel for antialiasing
Filtering - enables or disables the AA filtering for the current render channel
