GH2 GH2 and Green Screen

L

lifilmmaker

Member
Has anyone used the GH2 to shoot a green screen project?

Are there any issues shooting green screen work with a DSLR?

Can someone provide some links to GH2 green screen videos on the web?

Thanks!
 
Here's one I did over a year ago. The shots of the robot "assembly line" were one girl shot against greenscreen and replicated many times.


 
Erik,

Thanks for sharing your project. Nice job.

I'm considering shooting some web videos and researching if the Panasonic GH 2 would be a good choice DSLR to use. A cameraman recently informed me DSLRs are not good for shooting green screen work.

How big was the green screen you used?

Were the two girls walking also shot in front of the green screen?

What was your lighting set-up? How many lights did you use?

What did you use to edit?

Do you have any other projects you can share?

Thanks!
 
dvbrother said:
Here's one I did over a year ago. The shots of the robot "assembly line" were one girl shot against greenscreen and replicated many times.
Click to expand...

Nice! The hair and edges look really good.


lifilmmaker said:
Erik,

Thanks for sharing your project. Nice job.

I'm considering shooting some web videos and researching if the Panasonic GH 2 would be a good choice DSLR to use. A cameraman recently informed me DSLRs are not good for shooting green screen work.
Click to expand...
That's because people tend to get caught up on color space. To be honest, lighting things properly is more important that having 4:2:2.


lifilmmaker said:
How big was the green screen you used?
Click to expand...
10'x20'

lifilmmaker said:
Were the two girls walking also shot in front of the green screen?
Click to expand...
No. Just the bunette girl walking alone.

lifilmmaker said:
What was your lighting set-up? How many lights did you use?
Click to expand...
Lots. 3 just for the greenscreen, then 2 or 3 more to light the subject.

lifilmmaker said:
What did you use to edit?
Click to expand...
Premiere and After Effects.
 
Yep - use a GH2 for a weekly series that uses full green screen.

The key, as with any green screen setup, is good and even light. The camera, frankly, is secondary.
 
I just did a shot with my GH2. It has pretty fast motion in it and like a fool I didn't switch shutter rate (40) to anything faster, nor did I shoot in something faster than 24 fps so the motion blur is crap and doesn't key at all. Lesson learned. The rest of the shot though keyed smoothly.
 
Hi dvbrother,

Thanks for sharing your video.

I'll ask you the same questions.

How big was the green screen you used?

What was your lighting set-up? How many lights did you use?

What did you use to edit?

Do you have any other projects you can share?

Thanks!
 
Chris Adler said:
I just did a shot with my GH2. It has pretty fast motion in it and like a fool I didn't switch shutter rate (40) to anything faster, nor did I shoot in something faster than 24 fps so the motion blur is crap and doesn't key at all. Lesson learned. The rest of the shot though keyed smoothly.
Click to expand...

Hi Chris,

Do you have any video links you can share?

Thanks!
 
Progressive 4:2:0 does not have to be bad at all for keying. Think of chroma like the size of the pixels. With 4:4:4 each chroma pixel is exactly 1x1 pixels in size. With 4:2:2 each chroma pixel is 2x1 pixels in size or they are twice as wide. With progressive 4:2:0 your chroma pixels will be 2x2 pixels in size. So basically keying HD 4:2:0 is like keying a 960x540 image blown up.

Back when I used Apple Shake a lot for compositing I used to filter just the chroma pixels in DV material which was 4:1:1. By filtering I was able to soften the chroma channels and get a decent key. 4:2:0 is light years easier to filter and even without filtering can look very good.

What would be good to put in this thread is shooting methods with the GH2 that result in better keys. Keying is about edges and some modes and settings may give better results. I often wondered if the ETC mode would be better for keying as well since it is a raw 1:1 sample of the sensor. May have less edge artifacts and no aliasing on fine edges such as hair. Another trick we use in visual effects is to get rid of as much edge enhancement as possible. Shoot as flat and low detail as you can. This will make pulling a key easier. I sometimes wish the detail setting in the GH2 could be dialed down a bit more. It still has a bit of electronic sharpening when using Lumix lenses.
 
lifilmmaker said:
Hi dvbrother,

Thanks for sharing your video.

I'll ask you the same questions.

How big was the green screen you used?

What was your lighting set-up? How many lights did you use?

What did you use to edit?

Do you have any other projects you can share?

Thanks!
Click to expand...

I took my Lighting students on a field trip to a local soundstage and we shot that video as a class project. The greenscreen was a big, large cyclorama, though I could have done the same thing with a 6'x6', since she never really moved and I only showed her from the torso up. I only used one light: a Source 4 placed very high shining down on her from the lighting grid. I put a piece of white foamcore on the floor underneath her to bounce light back into her face and block green spill, as the floor was also green.
I edited in Final Cut 7, but did the keying in After Effects using Keylight. Honestly, I think I got a little lucky with the keying. It's the best 4:2:0 keying I've ever pulled off. I shot that with a Nikon 35mm prime, so perhaps the low-contrast and lack of electronic edge-enhancement (that occur with Lumix lenses) contributed to the good key.

I don't have any other greenscreen projects on GH2.
Thanks for watching.
 
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