Keying: Blonde Hair and Graininess on Black Shirts

[Ben Grace]

Trying to figure out how to edit my thread: my coworker actually showed me a pretty cool trick, somehow using the clip white as a mask? Not sure but basically he told me to copy the video and put it above on Screen Matte.

Then below it on the original video, delete the keylight and change it to the luma alpha chanel. This solved my grain problem (just have to do it to all 60+ video files) but the blonde hair is still an issue. Also, maybe you guys can give a name to what he showed me..was really useful!

[Ben Grace]

Thanks for the quick/incredibly helpful response Dave. Learning AE on the spot while trying to do work for a company has proved to be a challenge.

As you mentioned, doing the technique that my buddy suggested has worked well, except for dancers/players with long hair. There is some green that bleeds through on the back near their hair. I tried putting keylight on both copies of the video, but it doesn’t seem to work. For now, i’m going to continue composting the players with short hair that his trick does work, and hopefully figure out a work around for the dancers.

Also I really thank you for those links. THe problem I’m having with most tutorials is that they aren’t in depth: so many keys have so much difference. I watch a tutorial of someone simply keying out footage with no trouble. But then I’ll get video that is much trickier/different to key so I haven’t had a great chance to get acclimated. I’ll check out your links- if they provide video footage hopefully that can give me a better understanding of keying!

Also, I apologize for my ‘n00bness’. It’s always an adjustment period when you begin on a journey doing something you’ve never done before. I’m into guitar, animation, and now motion graphics; each time i dived into the community i always felt very stupid at first but after learning terminology and etc, learned a lot.

by the way, i’m not sure what the footage was shot with. We have some nice gear here: realme.com has the full list of cameras and etc, but its 1920 x 1080 and 30 fps. Also: I am working on implementing what you suggested but having a little trouble understanding exactly what you mean.

I’ll explain in more clarity what my co-worker suggested (again, which works except bleeds a little green through the back of some people)

1. Duplicate the Keyed video layer
2. Delete the keylight on the original video and keep it on the duplicate. Change the original to a luma matte.
3. Turn the duplicate to screen matte and turn its eye off.

What you suggested, would I follow similar steps but select alpha instead of luma? The actual keys look great, absolutely no white in the center of the person (probably due to good lighting/a clear green screen.) You mentioned to get a good key (which I did) and use it as an alpha layer. I tried duplicating my good key, changing the original to alpha, and deleting keylight on the duplicate. However it doesn’t seem to be doing antyhing, or going to straight white. Again, sorry for lacking knowledge in this area, i’m sure it makes it harder to understand what i’ talking about.

[Ben Grace]

ANy idea what to do if there’s significant green bleed on the back?

[Ben Grace]

Thanks Dave- yeah I did read what you wrote but didn’t quite understand it. When I apply keylight to the bottom layer (the alpha layer) and change it to have a greyish background, you can see the grey on the person’s face. I know this is annoying to answer questions for someone as new to this as me. To top it off, my boss just told me this is due in an hour and a half…my co worker suggested oolor correction to find the greens and desature them- i did that but you can still see quite a bit of green. I’m going to keep trying your method but i’m obviously doing something wrong.

edit- i realize what you wanted me to do dave. This issue is when i do the keylight plugin on the alpha matte, i get the grain on the image when it plays. I just applied it to all the video and then played them and realized it basically nulls out the alpha matte. What settings would I tweak to get it to be grey? I have it keying out the green, but maybe it should key out something else?

edit 2- on the second key on the alpha, i replaced the color with a much lighter green. Not sure why, but that seems to remove a lto of the green and the grain. Key still isn’t perfect, but i think my boss/client will hopefuly accept it.