Blackmagic Forum

HI guys,

When i used AE i saw i tutorial from "Corridor Digital" on green screens back in the day and they used a trick to make the green screen greener by managing the drop color in the "Keylight" to a lighter or darker green (whichever worked) in case you didn't have a good keying

i was wondering if it the same effect can be done in fusion ( pretty sure there is a way, but i still don't know)

Please guide me with you wisdom
and Thank you very much

(here is the video i was talking about)

You can grade the plate in any way you find fit before it goes into keyer. It is usually most helpful to pull the key, then start grading so that you can see the effect on mask interactively and adjust the keyer settings along the way if necessary.

To increase color separation you can try to saturate the plate, use hue correction tools or simply scale some color channels. The effect depends on the type of keyer used, color difference keyers react differently than, say, polyhedron based color separator keyers and so on.

In the end, good key is usually built up from different separate keys for different fg and bg areas that are keymixed together. And with fine detail you sometimes get more luck with non-alpha methods like grading the bg with specially treated fg element etc.

Edwin Rivera wrote:HI guys,

they used a trick to make the green screen greener by managing the drop color in the "Keylight"

Actually, they're not grading the screen, they're just using an interactive preview of the alpha channel to pick the best green to use as a key color. You should be able to do that with any node-based compositing app, by viewing the keying node's alpha out, while adjusting the keyer's key color.

In addition to Hendrik's suggestions, I would recommend having two passes, one to make the alpha and another to make the beauty pass of the RGB channels with proper grading. Then you don't have to worry about skin tones and other colors while cutting the matte, and you don't have to worry about the keyer when trying to make the beauty colors correct.