Realistic Keying Tips (Green Screen)

[Todd Kopriva]

There are a lot of tips and links to great resources here:
https://helpx.adobe.com/after-effects/using/keying.html

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Todd Kopriva, Adobe Systems Incorporated
After Effects quality engineering
After Effects team blog
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[Chris Wright]

color correct them to background, try color correction curves.

lightwrap color changes around edges, blur inner edges for light scattering, slowly fade edges transparently for lightwrap.

keylight can’t do any of those things because it sucks. that’s why its free. you can buy primatte keyer or ultimatte or something else usefull. google expensive keyers.

you also have the option of using your existing keys and merge them into my ae project which has those features setup from procedural mattes.

ae cs5.5 aep
https://f1.creativecow.net/7088/7088

[Chris Brett]

== also — dont forget to put your artists hat on — in some comps very small discrepancies in light and/or perspective give the game away ……….

————————————–chris–

[Doyle Lewis]

It’s always hard to say what to do for a key without a screen capture or a clip but the suggestions are so far very good. I would say that things to consider that generally get overlooked are:

color grading– not to be confused with color correcting. The first step to making a key look good after keying it is to match the color of the keyed layer to that of the background (color correcting), but the part that is often overlooked is color grading everything after. If you add an adjustment layer on the very top the foreground and background footage and do your final color grading it does a whole lot to make both layers look like they exist in the same environment. Just be sure to get it rather close in the first correction.

Light wrap– There are keying plug-ins that do this with nothing more than a checkbox (e.g. Red Giant’s Keying suite) but in AE I just make my own using the inverse of the matte from the key with a softened choke and place that over the original matte and use that combined matte as the matte on a duplicate BG footage with a strong Gaussian blur. Place this over your foreground image and lower the opacity greatly and you should get a subtle color mix around the edges of your keyed subject that make it look like the light from the environment lightly reflects off the subjects edges

Shadows– Make them subtle! Using AE’s 3D you can use a shadow catcher to do this but I prefer duplicating my keyed footage placing it where the shadow would fall. Remove the lightness and saturation, add a Gaussian blur, lower the opacity greatly and then draw a mask to mask out the section farthest in z-depth and feather greatly.

Shadows on your keyed subject – if something in the BG you are trying to place the subject in would cast a shadow on your subject, then with a mask on a black solid draw how that shadow would land and feather and set the opacity to match the hardness of the light.

Background animation– If the background is a still picture do some subtle effects to make it animated. e.g If there is a window in the picture then you can animate the brightness of the light it projects subtly through the shot so that it looks like clouds are passing outside.

Those are the only things I can think of right now but hopefully if you take your time doing those then you will get a well integrated composite.

Doyle Lewis, Assistant Videographer

thinkck.com