You can adjust the soft edge on each side:
Start: The start point in pixels to set up a crop
Length: Soft edge length – starting from the start pixel
Gamma & Gain: Adjust the transition curve
BlackLevel: You can adjust the grayscale outside of the soft edge. It can help reduce the double video black on the soft edges.

Need more help with this?
Don’t hesitate to contact us here.

Thanks for your feedback.