Clamping Channel Values

To clamp a channel’s values is to ensure that its blackest blacks and whitest whites are visible on an intended display device. Nuke’s Clamp node lets you assign “legal” values to colors that are either too light or dark for the intended display device.

Clamping black and
white pixels to “legal” values.
Clamping black and
white pixels to “legal” values.

For this effect, you use Nuke’s Clamp node.

To clamp channel values

1.   Click Color > Clamp to insert a Clamp node at the appropriate point in your script.
2.   Connect a Viewer to the output of the Clamp node so you can see the effect of your changes.
3.   In the Clamp properties panel, use the channels field to select the channel you wish to clamp.
4.   Drag the minimum slider to the legal value. (This has the effect of causing black values to go gray.)
5.   Drag the maximum slider to the legal value. (This has the effect of causing white values to go gray.)