Green screen should I shoot Tungsten or Daylight?

[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