Percentage Mode

Radii and expansion settings are usually specified in pixels. In percentage mode Blur 'N' Feather calculates the blur, mask radii, and mask expansion as percentages of the overall mask size. This allows you to render your blur to different resolutions without having to change Blur 'N' Feather settings. For example: a setting of 5 for blur radius will blur to a radius of 5 pixels in normal mode. In percentage mode, Blur 'N' Feather roughly estimates the diagonal size of the mask's bounding box in pixels, and sets the blur radius to 5% of that value. Consequently, far away/small objects will blur less than closer/larger objects.This is useful with animations where the source object moves towards or away from the camera.