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Monday
Feb012010

Feeling Green Pt.5

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dvMatte Pro Studio 3
FxFactory Pro (used for the spotlights on the BG)
CG Textures
Feeling Icky...

5DMKII Keyed Still @ 720p...
7D Keyed Still @ 720p...

Here's the Deal...

Obviously the footage isn't MOS. I thought I didn't record any audio but I realized that had the crappy audio from the cameras so I used that. Ladder behind me, if you were wondering.

As far as settings go, both cameras were near identical. The same picture profile (no sharpening, contrast down two notches and saturation down a notch). Both cameras were set to the same color temperature and I used Zeiss ZE primes on both. The 5DMKII had the 85mm and the 7D had the 50mm. This gave approximately the same effective angle of view on both (the 7D was at around 80mm with the 1.6x crop factor).

As far as frame rate goes, they were both set to 30fps. The only difference was that I accidently left the shutter on the 7D at a 50th instead of a 60th. I did a slight gamma adjustment in post to help match them up but other than that, zero color correction, sharpening, etc. was done in post. None. All clips were transcoded to ProRes LT before working with them in Final Cut Pro.

As you can see, the 7D's color is definitely different than the 5DMKII's. They both pulled keys pretty easily, but the 5DMKII was a little faster. I could definitely spend another 20-30 minutes on each and clean them up some more and also add a wrapped version of the BG to create an even more convincing key (DV Matte Pro comes with that plug-in). These aren't flawless keys and I could get more detail in the hair by working on the matte and also fix the 7D's slightly green look with color correction. That said, they keyed almost as easily as the EX1. The last time I tried to pull a key with the 5DMKII I had sharpening on and it was definitely harder than this time.

My overall conclusion is that with the right lighting and, very importantly, a good keyer both cameras can pull convincing & usable keys. The 5DMKII seemed to edge out the 7D a little and it was slightly easier to retain hair detail with that footage. I also like the color on the 5D footage more right out of the camera. It could be the different lenses, but both cameras are using brand new Zeiss ZE primes so that's probably not it. Not the first time I have seen a slight difference between the two cameras. Maybe a test with identical lenses is coming up!

Lighting wise, I did a high centered key (LED 600 Flood without a softbox), with a reflector below. I also used a rim light (LED 256). Sort of a beauty lighting set up. Nothing fancy. Just something to get pretty even lighting over her face. Could be better, but it got the job done.

That's it on green stuff for awhile. I feel kind of icky from all that green and want to go and shoot something that's real!

« 3rd & 7th | Main | Deep Thoughts... »

Reader Comments (13)

lovely kid

February 1, 2010 | Unregistered Commentervincent

which lights did you use on this ?

February 1, 2010 | Unregistered Commentervincent

Vincent,

I'm using the four foot flourescents for the green screen and an LED 600 for the key. That's bouncing off of a Photoflex multi-disc. I'm also using the LED 256 as a rim light.

-Jem

February 1, 2010 | Unregistered CommenterJEM SCHOFIELD

Great post!!!

I did notice on the side by side comparison that on the girl's forehead the 7D got a little blown out towards the end whereas 5D didn't have that issue, do you have any idea why? Different F-stops???

February 1, 2010 | Unregistered CommenterSteve

Steve,

Same exposure & set-up. The 7D was at a 50th as opposed to a 60th so that may be it. I did do an overall gamma adjustment to the 7D's footage, but that wouldn't necessarily have solved the entire problem.

The main thing is that both of these cameras can, if needed, be used for green screen work. They wouldn't be my first choice but they can be used.

-Jem

February 1, 2010 | Unregistered CommenterJEM SCHOFIELD

Yeah that could explain it...very interesting stuff, thanks for taking the time to do this side by side test, it's very helpful to see. By the way what do you mean by you could have added "a wrapped version of the BG to create an even more convincing key" - I'm not familiar with this concept of wrapping in regards to chromakey...anyhow, keep up the good work, you rock!

February 1, 2010 | Unregistered CommenterSteve

Steve,

She also leans forward at the end and there is more light on her at that point because the key is in front of her.

A wrap filter/plug-in allows you to take an image, usually your backplate, and use it to wrap light around the foreground (the talent). It basically applies the luminance from the BG image and wraps light around the subject to create a more realistic key. Most good keying solutions come with that.

-Jem

February 1, 2010 | Unregistered CommenterJEM SCHOFIELD

What ASA did you use on the cameras?

February 9, 2010 | Unregistered CommenterScott

800 ASA

February 9, 2010 | Unregistered CommenterJEM SCHOFIELD

Hi Jem-

800 ASA (ISO) is a fairly high rating to expect low noise. We've been rating the 7D between 200 and 320 depending on the lighting setup. Hoping for a clean key at 800 is probably a little ambitious. I understand the desire to keep the heat down and more flexibility on the stop, but I'm wondering if 800 is practical. Has anyone done a test on where the sweet spot is regarding noise on these cameras? I can imagine as the sensors improve, ISO's like 800 (or more) will become common for greenscreen work.

Paul

September 8, 2010 | Unregistered CommenterPaul G

Paul,

Lower ISOs are definitely better. I would say 640 or under, if possible.

Also try to use the 5DMKII and 7D's "true" ISOs. 160, 320, 640, 1250, etc.

I try to never to shoot over 1250.

You can definitely get a clean key at 800 ISO. I did on these videos.

Keyer you use can make a BIG difference. I use DV Matte Pro.

-Jem

September 19, 2010 | Unregistered CommenterJem Schofield

Good info -- Thanks.
We have the option of using a 5D or EX-1 for an upcoming greenscreen shoot. Both with nice lens package although the Canon lens set is superior. This will be a standard Interior Car shot in greenscreen studio. I think the 5D pulls off better photography, but at the sacrifice of the key which is important here. Is the 5Dworth it or the EX1 a better choice in your opinion? Will be an ideal set & lighting situation.

January 1, 2011 | Unregistered CommenterLes G

Les,

Definitely the EX1. No question. Much better overall for Green Screen.

Turn sharpening down and use the HD-SDI output if you can. That will give you 10 bit 4:2:2.

Even going directly to SxS cards you're better off with the EX1.

-Jem

January 1, 2011 | Unregistered CommenterJem Schofield

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