Outdoor Key

Paul F

Veteran
Seeing Sparky's post, I thought I would show a key in uncontrolled conditions. http://www.youtube.com/watch?v=STmRLhwpdrM

This is our first key trial. We wanted to see what we could do dropping a backdrop in full sun. Just straight sun on foreground and background. There is a reflector for the shadow under the brim.

This is an example of poor conditions that came out quite decent. The green screen was hot (full sun). The subject was quite close the the screen. Ignore the fact that neither shot was locked down well. I didn't have a reference point to stabilize the foreground and lock it to the background. We'll try that next time. We are experimenting with worst-case conditions of keying a subject outdoors with hand-held shots (not intentionally shaky) to see how well we can get it and eventually a try a tracking shot. This is AF-100 with the Lumix 14-140, 1/30. Keylight in After Effects.

While it needs a lot of work, I'm quite impressed with the background coming through the weave of the brim and the pink cellophane. Slow shutter speed is not an issue. The keyer deals with it quite well. The smoke has some issues and needs work.

Notes

Ignore the noise under the brim. That's a problem I haven't sorted out.
Yes, his hat and shirt are over exposed. I didn't see that on the monitor with the zebras. I'll try the waveform monitor next time.
Yes, the foreground is softer than the background. Same lens.
Ignore the rasterization. I forgot to tell AE that the material is progressive.

For my first key in uncontrolled conditions, I'm quite satisfied. I can see that with a little more work it can be quite good.

Rick - I'd like to read that thread about keys with multiple layers if you come across it.
 
Uh, i thought that was very successful for a test. I ignored the motion and just looked to see if i believed the subject matched the background, and it did very much. Quite something.
 
Paul,

Your quick and dirty test looks good. You say you're using After Effects? Are you using the built-in effects or a third-party plug-in?
 
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I'm using Keylight, which is included in CS5. I re-shot the material with reference marks so I can stabilize the foreground and track it to the background.

The rasterization I mentioned is not because of mis-interpretation of the source material, but seems to be an issue with the keyer. I'm reading up on how to get rid of it. It looks terrible. Once I have it sorted out, I'll post a clip with foreground, background, and final results.
 
I recorded to FLASH on the camera with AVCHD. I'm still having issues learning After Effects. I did find out that AVCHD is not to be used in AE. It needs to be converted to a full-frame codec. That fixed the rasterization. But now the rendered clip has coding issues. The background is very blocky and has no detail after rendering. It looks great in AE, but looks terrible once rendered; as though I am doing heavy compression and low bit rate. Not a top priority right now, but when I do have it sorted out, I'll post it.
 
Here is the material re-shot with a dolly push in. The objective here is to see if we can do some green screen tracking without the need for camera motion control; just doing it freehand.

The foreground and background were shot with a dolly. Both shots were moved by hand for the dolly move and the pan/tilt of the head. Each shot tried to track the reference point with using a mark on the monitor. Then stabilize the foreground and track it to the background.

The keying is not as good as I would like. There is still some noise generated by the key. I've been reading up on how to eliminate that. There are fixes noted in posts. Ignoring that, I am satisfied that we can do some tracking shots with the green screen.

But to the original point of the post, you can see (below) that we have a screen flopping about in the breeze with different luminance and that luminance moving about. Also, the slow shutter speed is not an issue. The subject is about 3' from the screen. Just sun. 1/30, Lumix 14-140, AF-100.

edit - also note that subject is standing on grass. So this is about as bad as conditions can get for a green screen and it works.

Foreground and background - http://www.youtube.com/watch?v=DNd3N-j-zTI
Composite - http://www.youtube.com/watch?v=qYmq73j7m2E
 
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