Line appears when I key and it's not from outside the mask
by Courtney Taniguchi on Nov 19, 2014 at 9:18:05 pm
Hi Creative Cow Community! I'm having some issues with keying in After Effects. We shot a subject against green screen, edited a rough in final cut 7, exported the cut in pro res, and keyed in After Effects.
What I've found to look great is this:
-Take the footage and clip a mask to remove subject matter from off screen.
-Use selective color - greens - push Cyan, yellow and black to 100% and magenta to -100%
-Keylight 1.2, clip black and white with a bit of clp rollback and screen pre-blur to 2.0
-Double the footage, remove the effects off of the bottom layer and alpha channel to the top layer so that the original footage appears in the key. View as final result.
-Color correct the bottom footage using levels, vibrance, and hue/saturation
-render out as pro res.
Trouble with this is that there is a line that appears throughout the video on the sides. It is slight and thin, but it is noticeable since my video does not have a complex background to hide it. It's been giving me hell in prior renders. Initially I thought it was because I didn't create a good mask and objects surrounding the green screen were creeping in. However, I did a new mask where I shrank it close to him and it can only be green screen where the line appears - you can see in the attached pictures.
I've included pictures of the comp, effects I used, the raw footage and the final render with the pesky line.
One of my coworkers suggested that whenever a blur effect happens, it can tamper with the edge of the mask. I'm wondering if something akin to that is happening because I have keylight effect on a small mask?