After you have applied degrain operations to the input image, you can isolate parts of the image to degrain using secondaries. Degrain operations are cumulative: after initial noise removal, multiple passes using secondaries on the same area will be added to the final result.

When applying a degrain filter to a secondary layer, you cannot use temporal options and cache degrained frames.

To degrain a secondary layer:

1. In the Colour menu, click Degrain.
2. Select a secondary layer. See Secondary Colour Grading.
3. (Optional) Add a geometry to constrain the area of degrain analysis and filtering.
4. Click Analyse.
5. To view results, click Apply Degrain.