buzzing keys.

[Charlie Edison]

Without getting in to a heated discussion about who has a better keyer,

(when in fact there’s really no comparison.. 🙂

here’s a few tricks,

I hope you using the resolve panels to isolate the keys using the soft knobs, ultimately the best way to refine your key!
Using HSL, work the low/high/soft saturation and low/high/soft luminance control until you get a better result, before reaching for the blur key knob, select key tab/button and then adjust the Qualifier “Gain” control.
This can help flood the key selection or inversely decrease the gain, then reach for the key blur, shrink grow.
Another helpful idea is to go hard at the qualifier, over do it a tad and then use output post mix to mix out the correction until you get the level of change you need.

It can be quite hard to qualify a color at the end of a bunch of serial nodes, try adding a parallel node that connects to a clean base grade (ie, node 1) and then key that and add the output of that back into your grade…

[Ola Haldor voll]

I seldom have issues with this. I had more problems with these kind of things in Color, but then again, the clients have developed new skills at the same time as me..

Would you mind posting an image of the problem shot of yours?

[Rick Turners]

Thanks Charlie, exactly what I was looking for!

I cant post an image for this here, but one example is a scene of two blonde haired white people sitting on a couch against a tan wall (which the key also picks up in the facial key) Also, the girls blonde hair is picked up as well.

The wall starts to buzz as it falls off into the shadow. (I fixed this with a power window)
The faces are fine, but the blonde hair buzzes like crazy as it moves around, falls into shadow etc etc.
It’s obviously an incredible qualifier, once you know how to manipulate it properly. 🙂

It seems as though by default, if the key is blotchy it will go nuts. With some manipulation in the Key tab it seems to be more forgiving.

[Illya Laney]

Rick Turners
“The wall starts to buzz as it falls off into the shadow.”

What’s the footage source? If the wall starts buzzing as it falls off into the shadows, you’ll need to adjust the lum low clip and lum low soft to create a softer ramp into the shadows.

Keying blonde hair can be difficult even in dedicated compositing applications. As an example, I have a friend who had to roto hair for a week because they needed perfect mattes for a stereo film, and this was even shot in front of a very well lit green screen. If it’s a fairly light blonde, try using just the luminance with low saturation parameters. If you keep the hue in, it’s going to be pretty much impossible to totally isolate the hair because it overlaps with skin tones and the tan wall.

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