Additive keyer with grey screens?

Got a bunch of screens coming up that I’d usually use an additive keyer on, fg people are soft but the bg screens are sharp. However, the screens are grey rather than green.
Can anyone give any advice at all on a way of keeping those soft edges of the fg looking good similar to using an additive keyer? Or would additive keyer still work?
Thanks in advance

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I’ve managed to do something which I’m surprisingly happy with but would still appreciate any suggestions

Some of the things I would try:
A saturation key, seeing if one of the individual color channels can act as a matte, multiplying the plate against the BG image for the soft edge areas

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Thank you Greg, I’ll give this a go in the morning

Hey @Robg

I like to get the screen inserts into position then use them to grade my grey screens. Darkening the shadows and lifting the highlights.
You’re aiming for an additive key look. If your screens are close to mid grey you can even 50% blend your screen inserts and them increase contrast on the screen comp.

Additive keying means getting really good edges but your foreground is transparent. You’ll need roto to fix the transparency.

If your edges are too dark then use offset to lift them slightly.


I think I know what you mean, I’ll give this a try in the morning and see where I get to. Grey screens are new to me with objects/people in front, I usually request green for this but I’m looking forward to learning as I’m seeing grey a lot more recently

The danger with green or grey is that they can easily get too bright when captured by the camera. If they are too bright you loose all reflections plus getting any dark bits of footage into the screen can be compromised due to the glow and bleed a bright screen gives off.

Unless I am going to be on set to control the brightness I always insist that the screens are off.

The advantage to this is that I can guarantee that if there are any reflections, I will get them and the key to a good looking screen comp, in my opinion, is nice looking reflections.

You have the problem that the foreground will be over a dark screen but I usually suck that up and do roto.

Sometimes the DOP will insist that there is some illumination from the screens but make sure that they have the brightness way down.

I find that any flicker or brightness they introduce never matches the footage they want me to insert. If that can have that light off screen slightly. All the better for everyone.

Did a job recently were they hung flickering led tubes in front of the television. What a nightmare.

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I think I’m in a minority here but I hate screens turned off. DOPs just don’t seem to have the time to light something they can’t immediately see. I spend most of my time painting out reflections. My hope is that with screens on, DOPs would light them the screens with less reflection and in the main it sort of works. It would be great to have stuff shot for real. Take a look at Roger Pratt’s work in Brazil

Those fruit based adverts were shot for real and not too difficult to comp after the fact.


Some of my best screen comps were grey and I was on set to control the brightness.

Some of the worst were (bright) grey and I was not on set :stuck_out_tongue_winking_eye:


Just gone through my comp I did yesterday and multiplying against the bg image is how I did it, a few more tweaks and I think this is how I’ll move forwarded with this shot.
Thank you again Greg

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Definitely very thankful that these are perfect 50% and the spill is minimal, looks like they’ve shot and lit it how you’d like it.
Also who hangs flickering led tubes in front of a television!! Maybe they just thought they’d give you even more of a challenge for fun!