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Sony NXCAM NEX-FS700 CineAlta
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Old February 24th, 2013, 07:35 AM   #31
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Re: Disappointing image quality, especially for chroma keying

I find that chroma keying in Final Cut or Premiere Pro to be a waste of time. At best it looks like a local TV weather cast segment.
Compositing is best done in After Effects.
Here is a great tutorial dealing with less than perfect keys courtesy of Andrew Kramer VIDEO COPILOT | After Effects Tutorials, Plug-ins and Stock Footage for Post Production Professionals
I think that everything in this tutorial was shot on the 7D so we're not talking about 4:4:4 colorspace.
The key you can get with this technique is pretty amazing and can really save the day and doesn't take too much time.

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Old February 24th, 2013, 12:44 PM   #32
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Re: Disappointing image quality, especially for chroma keying

The Ultra Key effect in Premiere Pro is particularly good, and with CUDA acceleration, it's a render-free option, which results in huge efficiency when you're dealing with lots of footage.

With proper lighting, any camera can produce very good results for most applications.
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Old March 13th, 2013, 05:18 AM   #33
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Re: Disappointing image quality, especially for chroma keying

Quite badly lit. Green spill everywhere. The camera does not light the scene for you, nor does it tell you how to get a proper greenscreen. Get some distance to the actor and the greenscreen, and light them separately.

Composition also seems to be quite "not done". Keylight needs some work, it won't magically do stuff for you. Ofcourse the leg will show through, it's completely full of green spill!

Ultrakey in Premiere is also...not very good. Except for speed. There are really no one button solutions. Primatte for Fusion is pretty nice.
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Old March 16th, 2013, 06:57 PM   #34
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Re: Disappointing image quality, especially for chroma keying

Dominik, have you shot that in SloMo?
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Old March 19th, 2013, 09:04 AM   #35
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Re: Disappointing image quality, especially for chroma keying

I agree the lighting and proximity of the talent to the green screen is far from ideal for a good key. I also agree there is a focus problem. There seems to be some comments which indicate the software doing the keying is a major factor. I believe its much more of the above. If everything is done correctly (yes of course that's a big if) FCPX will key extremely well without any adjustments at all. In fact, that is quite a clue you have done your setup correctly. I have read there have been folk doing tests with green screen work using 4.2.2 vs 4.2.0 and the results were not as substantial as expected. In some cases the result was marginal and the 4.2.2 introduced much more noise which caused additional problems. Finally, a hint I read about and worked well for me is to reduce any sharpness/detail settings to as low as possible. You can sharpen quite a bit in post after you have gotten the key.
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Old August 6th, 2013, 08:59 AM   #36
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Re: Disappointing image quality, especially for chroma keying

Hey guys, I've read all your posts and it's been helpful. I have a green screen shoot coming up and since most of you have already shot greenscreen footage with the FS700, what technical advice can you give?

Which would be the best picture profile to use?
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Old August 8th, 2013, 07:42 PM   #37
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Re: Disappointing image quality, especially for chroma keying

I'd recommend using the picture profile that will provide the best gamma match to the background plate - that makes the foreground (person) look the way you want them.
Just don't deviate too far from the norm on your matrix settings. I wouldn't recommend trying it with an S-Log type profile.
Realistically, if the green is properly lit it will probably all fall around 52-55 IRE, and in that range it will not be overly effected by the PP selection, so just make sure your foreground looks right and the lighting is perfect.

On the hardware side, I would think that if you had the latest firmware upgrade and an ext recorder and could do it in 4k that would be amazing...
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Old August 24th, 2013, 08:34 PM   #38
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Re: Disappointing image quality, especially for chroma keying

I found green screen keying on this a breeze (rotoscoped the rest with edge define) all done in after effects CC
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Old August 25th, 2013, 10:07 AM   #39
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Re: Disappointing image quality, especially for chroma keying

Some basic tips for lighting chroma key setups, rehashing what some other folks have already said, but condensing it into a quick list...

1) Even lighting on the screen - flooded lights or broad sources are best (LEDs can work well. So do Kinos)
2) Expose the screen at around 50 IRE. If you have a histogram on your camera, that means "mountains in the middle."
3) Get a good amount of distance between the back of your subject and the chroma screen. This prevents green (or blue, depending on your screen) reflection "spill" on your subject. But, it also helps to isolate your lighting. Dedicate separate lights for the screen and for the subject. Control of your key light spill is pretty important, since it's likely to cause one part of the chroma screen to receive more than another, which serves to damage the uniformity of the color you're going for. With added distance from the key, the screen gets less unwanted light spill due to fall off.
4) Expose skin tones around 70-75 IRE, with whites going up around 95 IRE.
5) A nice back light on your subject for added edge refinement, being careful not to shine it on your lens
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Old August 26th, 2013, 07:50 PM   #40
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Re: Disappointing image quality, especially for chroma keying

Hi

My 2c.

Keep the subject as far away from the screen as possible .... Ie you need as big a screen as possible.

Make sure the screen is true chroma green ( paint or fabric or paper). Buy the best. Don't eyeball it!

Light the screen separately from the subject ... Put chroma green gels over the light sources.

Don't white balance using a white card near the green screen set!!!!!! green spill will ruin everything!

expose for the screen ( 60 -70 % ) then light the subject as required. If you have to err... Go over on the subject. You can bring it down in post.

Back light the subject.!

Getting the floor to key right is hard

Try the keyer in FCPX ... It is really killer.
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Old August 27th, 2013, 01:10 AM   #41
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Re: Disappointing image quality, especially for chroma keying

My tip is to use minus-green (magenta) on the backlight/rim lights. It cancels out green spill.
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Old August 27th, 2013, 02:14 AM   #42
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Re: Disappointing image quality, especially for chroma keying

and my tip is use a waveform monitor to check your evenness of lighting. If your lighting is reasonably even, your WFM will have a straight line across it.
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Old September 7th, 2013, 11:42 PM   #43
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Re: Disappointing image quality, especially for chroma keying

Gee I looked through this whole thread before going back at looking at the stills.
Yes garbage in garbage out. Something is wrong with your lens and Alistair is probably right its likely back focus is way out on the speed booster. A lot of people don't understand how to set back focus with a zoom lens. It needs to be right on the money.
Plus - what are you using as a green screen material? Doesn't look like proper material to me at all. No saturation and too wrinkled.

Please don't blame the camera for this
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Old November 22nd, 2013, 06:33 PM   #44
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Re: Disappointing image quality, especially for chroma keying

Chromakey can be tough . . . the background lighting is usually the culprit; of course, the use of proc amps, filters a tong of 'tweening on the post side; I see hot spots on the background lighting, and certainly uneven levels - which is tough to get a clean key from.

I use to use muslin green backgrounds; before that, I painted cycs with blue screen paint (not cheap!) I use LED chroma key rings and backgrounds now, and always get easy, clean keys!! (Chroma key light ring and retro-reflective backgrounds. Green screen.)

You may want to consider retro reflective backgrounds and led technology - here are some suppliers . . .
DATAVIDEO LD-1 CHROMAKEY RING | Datavideo

Reflecmedia: Changing the art of chroma key

and a really cool led light ring for TELEPROMPTERS at Chroma key light ring and retro-reflective backgrounds. Green screen.
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Old November 23rd, 2013, 03:25 PM   #45
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Re: Disappointing image quality, especially for chroma keying

I was just looking around for some examples of green screen footage I've shot with the FS700 and remembered that I shot all the green screen for Chris Landreth's "Subconscious Password" with two FS700s in CineGamma 4. I was the DP and stereographer. It was recently shortlisted for an Academy Award nomination.
We shot most of it at 4 and 8 frames per second and recorded direct to ProRes422HQ (and AVCHD for backup.)

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