Contract or shrink a Feather

I am using Avid MC 8.4 on a workstation computer. I added the BCC effect Light Leaks and used pixel chooser with Mocha to create a mask inside the effect. I get the matte pretty close but when I add a feather it brings out the black around the talent. I would like to shrink the mask or contract it a little to feather the talent and the background (black). This option is not in the pixel chooser. I supposed there is an option in Mocha to do that?

Also like in Pixel chooser I want to invert the unchosen mask to show the area around the talent and also see the choosen pixels as a mask. Can one get this view up in Mocha?

Try a feather of two pixels instead of a large feather, that should fix the issue. Also, you can use the uber key inside of mocha to bring the sides of the roto in a little bit farther.

Please let me know if that works for you, and if you have any more questions I will be happy to help you.