Processing and Formatting Effects > Flame FX > Depth Of Field >
Z-Depth Settings

White Value box
  Select whether white pixels represent the furthest point or nearest point on the Z-axis.
Premultiplied Depth button
  Enable to have the alpha channel information premultiplied with the colour depth data. Use to prevent a black halo from forming around blurred areas.
Max Blur field
  Displays the maximum total horizontal and vertical blur by the entered amount. The cumulative effect of the high blur amount (Basic tab), and gamma and gain correction applied to the Depth map (Depth tab) may result in very large values, which greatly increases the processing time. Use the Max Blur amount to clamp the value and avoid some unnecessary processing.
Slopes field
  Displays the gamma curve level applied to the Z-depth map before it is used.