Green screen should I shoot Tungsten or Daylight?

[BigLu]

I am shooting a music video on a full green screen stage.
I have been told in the past that the RED camera likes to see Daylight White balance and is designed for daylight.

Im not sure what that means %100
but its been described to me to always try to correct my lights for daylight instead of tungsten lighting.

So on a green screen should i used daylight bulbs when possible on the KinoFlow lights, and for thats that I cannot change out should i blue gel them?

Is that the best method?

Thanks

[Gunleik Groven]

I have done some tests lately. RED may well like daylight better, but it keys like nothing else even under tungsten.

But: Do a test and see if you§re happy

[Herring]

If you don't mind some extra glass in front of your lens, you can consider a 80A or B filter. But you lose 2 stops...

[Hans von Sonntag]

REDs sensor is 5000 Kelvin. Tungsten is 3200 Kelvin. The red channel will clip considerably earlier and the already noisy blue channel gets even noisier, additionally sensitivity decreases from 320 ASA to approx.250 ASA.

WB the camera on set with filter does make a lot of sense if DR and noise are of concern. For pulling a good key this matters a lot.

Thus, shooting in tungsten with a 80A or lighting the whole set with daylight is reasonable.

I shot a curly haired talent in front of a daylight lit greenbox and was very pleased with the results. Doing the same with tungsten in front of a bluebox would have created a less nice key.

Would one shoot with daylight balanced film in tungsten lit greenbox?

Hans

[Bruce Allen]

Agree with everyone above... daylight.

Bruce Allen
www.boacinema.com

[Dominic Jones]

Well, got a shoot Thursday which will (for budgetary reasons) be Tungsten lit, no filtration (not enough stop - budget again), WB in post.

A little nervous about it now, but will post results once I'm able to. I'm also keying the final shots, so it will be interesting to see exactly how it pans out in less than ideal circumstances.

BTW, I haven't got any time to do tests (still putting the camera package together!) which is a bit of a worry - anyone know any particular gotchas I should be aware of (specific to Red ChromaKey shooting under Tungsten light - I know how to light a ChromaKey shot in general!)?

[Bruce Allen]

Well, got a shoot Thursday which will (for budgetary reasons) be Tungsten lit, no filtration (not enough stop - budget again), WB in post.

A little nervous about it now, but will post results once I'm able to. I'm also keying the final shots, so it will be interesting to see exactly how it pans out in less than ideal circumstances.

BTW, I haven't got any time to do tests (still putting the camera package together!) which is a bit of a worry - anyone know any particular gotchas I should be aware of (specific to Red ChromaKey shooting under Tungsten light - I know how to light a ChromaKey shot in general!)?

Dominic, to be on the safe side, just assume you're going to crush the blacks and that you don't have any more dynamic range than HDV and you'll be fine.

The biggest gotcha I hit was overestimating the dynamic range due to listening to Reduser too much. The shadows are noisy - keep eveything you're keying in a nice 6-7 stop range and you'll be golden - should key like a dream.

Related to this, I know the Red LCD is supposed to be showing a 709 preview and that there's more dynamic range available in the RAW file, but I wouldn't bank on it. Make it look good in the EVF or LCD and you'll be okay.

Definitely do not rate the camera beyond 320ASA. Be extra careful if you're shooting 2K because you're using 1/4 of the sensor and it is consequently far more noisy.

People may take offense to this post as bashing Red or whatever, but who cares - I'm trying to help.

EDIT:
You should also rethink your budget. HMIs or Kinos aren't THAT expensive. If your rate is $60/hr for doing effects, then why the hell not spend an extra $180 on lights for the day. It could easily save you more than 3 hours' work in post if you're doing tricky stuff.

Bruce Allen
www.boacinema.com

[John Brawley]

I am shooting a music video on a full green screen stage.
I have been told in the past that the RED camera likes to see Daylight White balance and is designed for daylight.

Im not sure what that means %100
but its been described to me to always try to correct my lights for daylight instead of tungsten lighting.

So on a green screen should i used daylight bulbs when possible on the KinoFlow lights, and for thats that I cannot change out should i blue gel them?

Thanks


Just did some extensive green and blue screen testing both under daylight and tungsten settings. (over 100 setups with all the variables !)

We found we got the best results lighting with supergreen kino tubes on digi green screens, with daylight balanced FG/

Even under and overexposed shots could be pulled on tungsten and regular (not supergreen kino's) but they weren't as nice.

Every little bit helps.

jb

[Hans von Sonntag]

Definitely do not rate the camera beyond 320ASA. Be extra careful if you're shooting 2K because you're using 1/4 of the sensor and it is consequently far more noisy.
Bruce Allen
www.boacinema.com

Exaxtely.

RED in 2K windowed is much noisier than in 4K. 2K windowed is not a good mode for keying. But 4K downconverted to 2K or 1080p creates a very rich colour space. IMO as good as 35mm.

Hans

[Joel Kaye]

We found we got the best results lighting with supergreen kino tubes on digi green screens, with daylight balanced FG/


Do you have to keep the talent further from the GS with those supergreens? Do they increase spill? I guess I'd be tempted to hit the talent with a daylight kicker.. but it's gotta match what you're keying into.

[Hans von Sonntag]

To reduce spill it makes sens to light the screen with a flat angle from above or below. The reflecting greenish light will hit the floor or the ceiling but not the subject so much.

Making the screen super-green with extra green lights does not help the key much - a big colour space in the footage (eg. 444 vs 311) does.

Hans

[Dylan Macleod, CSC]

You will get a less noisy image if you light daylight...cause that is what the sensor wants.

I have heard that with green screen it is not such a big deal if you have to light tungsten.

Bluescreen, however can be problematic because it is in the blue channel that the noise first appears. If you are lighting a "daylight" sensor with tungsten i.e. "yellow" light you are essentially lighting the chroma out of the blue which will cause noise.

Not "unusable", but certainly not ideal.

Dylan Malceod
Cinematographer
Toronto, Canada
www.dylanmacleod.com

[Joel Kaye]

"yellow" light you are essentially lighting the chroma out of the blue which will cause noise.


Would you be inclined to light even non GS scenes with daylight bulbs and gel practicals in the frame towards daylight when possible? Or is that too much hassle for the benefit?

[Dylan Macleod, CSC]

Would you be inclined to light even non GS scenes with daylight bulbs and gel practicals in the frame towards daylight when possible? Or is that too much hassle for the benefit?

This is a good question and everyone will have their own approach. Personally...I am going to do some testing of lighting night scenes with all daylight (unless i want a "warm" effect). For me this is relatively easy because I love kino flos and it is simple just to use daylight bulbs instead of tungsten. HMI's tend to be used on night scenes, so adding a little gel for "moonlight" is not a problem.

My feeling is that you will get a much cleaner image.

Of course, this is not always appropriate, so it may be that you light with tungsten when you want that "gritty" look.

I get my camera soon and really can't wait to find out all the possibilities this camera has to offer. The tungsten/daylight thing being one thing to play around with.

Dylan Macleod
Cinematographer
Toronto, Canada
www.dylanmacleod.com

[Frank Weeks]

BigLu

Make sure your back lighting is strong enough and try using amber gels (green screen) over your backlights. It can help to enhance the key. Make sure to test first.

Good luck

Frank

[Dominic Jones]

You should also rethink your budget. HMIs or Kinos aren't THAT expensive. If your rate is $60/hr for doing effects, then why the hell not spend an extra $180 on lights for the day. It could easily save you more than 3 hours' work in post if you're doing tricky stuff.


Mate, I'd absolutely love to - no chance. Running right up to budget as is, and the kicker is I've got a pretty extensive tungsten package I can bring for free. Also, still waiting on various kit for the Red package, so having to rent in some short term solutions (lens package as haven't got Nikon mount yet, etc).

Thanks a bunch for all the info - that was pretty much my plan anyway (light as normal for digital and crush down), but it's good to get some verification. Man, I wish I had time to do some tests and/or a bigger budget... Oh well, such is life!

[Ivan G]

I remember coming across a thread with these test images. It clearly looks cleaner to use daylight.

[Bruce Allen]

Mate, I'd absolutely love to - no chance. Running right up to budget as is, and the kicker is I've got a pretty extensive tungsten package I can bring for free. Also, still waiting on various kit for the Red package, so having to rent in some short term solutions (lens package as haven't got Nikon mount yet, etc).

Thanks a bunch for all the info - that was pretty much my plan anyway (light as normal for digital and crush down), but it's good to get some verification. Man, I wish I had time to do some tests and/or a bigger budget... Oh well, such is life!

Don't worry, I'm sure we'll be reading a delighted follow-up post from you on how well it all went. Good luck!

Bruce Allen
www.boacinema.com

[Dominic Jones]

Let's hope so!! Cheers again mate, will definitely report back once I've had a look at the final images and how they key....

[Andreas Höhn]

you an find a good article on kinoflo page HERE (http://www.kinoflo.com/FYI/FAQs.htm#3)

we have done different green screen shots with green tubes, tungsten and daylight. our red #590 did excellent under all conditions. But it were simple shots under controlled environment.

[Tail Ends]

John, Bruce and others to this thread: Are you using any on lens/mattbox filtration to modify your light when shooting green screen? I have a thread going in this section on filters and would appreciate any feedback from you guys as to what you believe to be a decent selection of filters to cover "normal" situations. I find that film DP's seem to have a slew of filters in their pack, while most HD types lean to the modify in post philosophy. Comments please.

Tail Ends

[Bruce Allen]

Tail Ends, no filters if shooting daylight balanced greenscreen in a studio. If shooting tungsten, consider the 80A as Hans says.

I love the glimmerglass, lowcon, grads, polas, etc as much as anyone but in a controlled lighting greenscreen studio environment there is no need for them and diffusion / flares around highlights etc get in the way of the key. I can imagine you could make a case for using a pola once in a blue moon?

Bruce Allen
www.boacienma.com

[Tail Ends]

Bruce, Formatt has filters for shooting blue and green screen specifically. I've never used any of these, but so many people are shooting blues and greens these days, there must me a reason for the filter or it wouldn't cost $700 plus (each)!

Tail Ends

[Bruce Allen]

Bruce, Formatt has filters for shooting blue and green screen specifically. I've never used any of these, but so many people are shooting blues and greens these days, there must me a reason for the filter or it wouldn't cost $700 plus (each)!

Tail Ends

Wow, I'll have to play with one. I think a proper Red filter test is in order soon (waiting for Build 16 and for the new IR-reducing NDs though...). Want to get a hold of those Vantage blue anamorphic streak simulation filters too.

I can understand the whole coral / red tint might be nice, as you usually have to add a coral tint back in post to compensate for the key.

Bruce Allen
www.boacinema.com

[Anders Holck]

I have a key shoot coming up and will try the 80A setup.
I prefer to use spacelights for screen illumination so I'm tied to using tungsten filaments.

[donatello b]

"We found we got the best results lighting with supergreen kino tubes on digi green screens"

using firmware 13 - found super green kino tubes to be the worst with digiGreen screen .......

seems firmware 15 has improved blue channel & Red channel may have some improvements with less clipping ?... haven't used super green kino's with 15 yet ..

yoiu might shoot some test before the shoot ...

[John Brawley]

John, Bruce and others to this thread: Are you using any on lens/mattbox filtration to modify your light when shooting green screen?

Tail Ends

I sometimes will use a pola as it can often suppress spill and screen contamination on highly specula surfaces. You gotta be able to take the 1-2 stop hit though. Not always an easy ask.

jb

[John Brawley]

BigLu

Make sure your back lighting is strong enough and try using amber gels (green screen) over your backlights. It can help to enhance the key. Make sure to test first.
Frank

I find this to be a bit of an urban myth. And it doesn't work if you're fg lighting doesn't call for an amber backlight.

jb

[John Brawley]

Do you have to keep the talent further from the GS with those supergreens? Do they increase spill? I guess I'd be tempted to hit the talent with a daylight kicker.. but it's gotta match what you're keying into.

There is a perception that the super green and super blue tubes increase spill and contamination. I usually find the biggest issue is that people don't use enough separation from the key surface and FG and expose it properly. They are simply too close to the key surface.

The supergreens are very intense and I will often turn tubes off to bring the level back to base exposure or just under.

jb

[Finner]

The biggest gotcha I hit was overestimating the dynamic range due to listening to Reduser too much. The shadows are noisy - keep eveything you're keying in a nice 6-7 stop range and you'll be golden - should key like a dream.

Bruce Allen
www.boacinema.com

A lot of people are going to get caught overestimating the DR. From everything I have seen the camera tests out at 8-9 stops of DR max. Many digital HD cameras have better DR and film blows it out of the water.

With accurate information on the camera both its capabilities and limitations a person can make red footage look very good. Unfortunately there is a lot of bad information given on this forum and that helps no one.

[reality]

Likewise, I've tested a definite 10 2/3 stops.

[Finner]

Likewise, I've tested a definite 10 2/3 stops.

How did you determine 10 2/3? I would like to see the test where you found it to be that high.

Every highly experienced DP that has tested and comented on the camera has placed it in the 8-9 stop range, which is the same as I have found.

[reality]

We shot a stouffer chart and put it through redalert and then through a Lustre. I'll get the files from the post supervisor to post.

What tests did you do to determine 9 stops?

[Finner]

Real world shot with items lit by bright sun to items in shadow with a 12 stop range shot at multiple stops (film style). Nothing held up or was usable with a spread greater then 9 stops. I don't get paid by clients to shoot charts, hence for me charts mean very little and it is the actual picture and how that holds up that matters.

IMO stating 10 2/3 stops is exactly the bad inacurate information that gets people in trouble. Like Bruce mentions keep green screen safe at 6 to 7 stops and I would recomend keeping non green screen shots safe at a 8.5 stop range.

[reality]

Well, doing completely uncontrolled tests that are at best inaccurate like you're doing qualifies as BAD inaccurate information. You're providing a subjective interpretation of a very small sample set of shooting conditions and claiming that as good accurate information?!!

How exactly are you determining what the usable range is?
What is relationship between the total range captured and 'your' usable range?

Talk about the pot calling the kettle black.

[Finner]

Well, doing completely uncontrolled tests that are at best inaccurate like you're doing qualifies as BAD inaccurate information. You're providing a subjective interpretation of a very small sample set of shooting conditions and claiming that as good accurate information?!!

How exactly are you determining what the usable range is?
What is relationship between the total range captured and 'your' usable range?

Talk about the pot calling the kettle black.

Well you are wrong, wrong and a little bit more WRONG.

Exposure data scene shots are a test that is used by people who get paid to shoot things other then charts and reveal actual useable information. Follow the link below and surf the site a little. I hope you can learn a little and graduate from shooting charts that tell nothing of real world shooting.

http://www.kodak.com/US/en/motion/products/negative/data5219.jhtml?id=0.1.4.6.8.6&lc=en

[Evin Grant]

Chill out you two!

You're both actually right. In general 9 stops is what I've found to be the usable range while keeping the shadow noise level in check at ISO 320. That does not mean there isn't any more range down there just that if you decide to use it you must trade off a greater amount of noise. This is less of an issue in daylight than tungsten, but I have shot a music video at ISO 640 that definitely had 10 stops of visible (Real world) range but was also much more gritty/grainy than I think Finner would accept. Theses are the trade offs currently. I will usually shoot at 400 ISO myself because a little texture doesn't bother me as much as a blown highlight.

[reality]

Well you are wrong, wrong and a little bit more WRONG.

Exposure data scene shots are a test that is used by people who get paid to shoot things other then charts and reveal actual useable information. Follow the link below and surf the site a little. I hope you can learn a little and graduate from shooting charts that tell nothing of real world shooting.

http://www.kodak.com/US/en/motion/products/negative/data5219.jhtml?id=0.1.4.6.8.6&lc=en

I'm not wrong and you're tests are anything but accurate. It's solely based on YOUR subjective conclusions which are not by the right of your god, absolute truth like you want everyone to believe. If you're going to trash everyone else for being wrong and yourself for being the word of truth, prove it. Proving it means showing the end result on film, digital projection, tv, etc. after a full DI. There are so many factors that you ignore but you're a god to yourself so you must be right.

And, I drive a dodge stratus and I manage FIVE people so I am right!

[Graeme Nattress]

Since working with RED, I've learned a few things about dynamic range and it's testing....

1) it's controversial.
2) you've really got to test it yourself. If you look at someone else's test, you've got to fully understand how it was made and how valid that test is. It's easy to allow sources of inaccuracy to creep in.
3) DR is noise limited. That means that the eventual answer you come up with is limited by your tolerance to noise.
4) noise can be measured, but two different noise sources can have the exact same measured noise, but look very different to the human eye, so you can't "just" go by the numbers.
5) the test has got to be in one single frame if at all possible. The more frames you need to shoot to cover the test, the more room for human (and other) errors
6) it's got to be repeatable. That means you should be able to set up your test on another day, and get the same result.
7) given even all of the above, different people will get different results.

If you shoot a subject with the RED that has a very high dynamic range, the biggest problem you face is grading it. I have some shots here that a single curve will not grade the shot so you can keep detail in the highlight, and allow you to see the detail in the deepest of shadows. I have to move to secondary colour correction, area based, masks, windows and adaptive stuff to bring up the shadows to see their detail.

Graeme

[Bruce Allen]

Reality, I get > 9 discernible stops on my frikkin' HV20 with my Stouffer T4110C but that doesn't mean it has > 9 usable stops for production.

I have worked on 2 broadcast Red projects that had to resort to roto because of too much noise. One of them I was sadly involved in shooting, the other I was only involved in post. Both of them simply overestimated the amount of detail the Red would hold in the shadows. A high-profile Flame compositor friend complained about exactly the same thing with footage he was given.

Subsequently when I shoot Red I plan from the beginning to crush the blacks in post, so make sure to keep what I wanted within a smaller range of around 7 stops, like a normal digital project.

Finner is just trying to give good advice to people not to be misled by anything you read on Reduser, especially any Stouffer charts with crazy figures. Trust your eyes and don't think shooting RAW can do miracles. Light it right on set.

Bruce Allen
www.boacinema.com

[Finner]

There are so many factors that you ignore but you're a god to yourself so you must be right.


Funny, your wife calls me "Oh, my God!" also.

[Evin Grant]

Can we please keep the gods, wives and Doges out of this. I know it's fun but the topic at hand is dynamic range not domestic free range.

[Jason Sinclair]

Getting back on subject *cough*; Now with dynamic range all we can do is compare chart tests with 35mm chart tests if we are to compare and then the numbers matter. So if someone says the dynamic range is between 8 and 9 then what is films by the same argumentation of particularities? Is it 5 stops difference in people opinions or something less because my eyes are seeing something less.

[Dylan Macleod, CSC]

Chill out you two!

You're both actually right. In general 9 stops is what I've found to be the usable range while keeping the shadow noise level in check at ISO 320. That does not mean there isn't any more range down there just that if you decide to use it you must trade off a greater amount of noise. This is less of an issue in daylight than tungsten, but I have shot a music video at ISO 640 that definitely had 10 stops of visible (Real world) range but was also much more gritty/grainy than I think Finner would accept. Theses are the trade offs currently. I will usually shoot at 400 ISO myself because a little texture doesn't bother me as much as a blown highlight.

I agree.

The two bickering children are both right.

I test both ways. I do controlled tests with charts. And I take it out in the field.

Both methods teach you something and are valid...

Dylan Macleod
Cinematographer
Toronto, Canada
www.dylanmacleod.com

[Harry Clark]

And BTW, the thread was about daylight vs. tungsten. I was going to suggest that if you're on a tungsten-lit stage, and you need some stop, then an 80D is a nice compromise. It only takes 2/3 stop away, and it's a -56 (I think) Mired shift which gets you from 3200 to 4000. If you can afford a quarter blue on all your lights then that helps too. But I've done two tungsten-lit greenscreen jobs so far with my Red, and the 80D seemed fine from a blue channel noise point of view.
Cheers,
Harry

[number6]

I know it's fun but the topic at hand is dynamic range not domestic free range.
:) :) :)
Other than that, I have nothing to contribute... I'm just here for the take-away.