Tungsten on green screen with daylight on talent??

[Paul Kalbach]

When I was at NAB, somebody working at the Litepanels booth told me that when shooting green screen, RED will produce a better key if the green screen is lit with tungsten balanced, while talent is lit with daylight balanced (keeping tungsten spill off talent of course). I've never heard of this! I've always assumed daylight/daylight for the best RED key. Comments anyone?

[Cam Crowley]

Having shot some really bad (ie noisey) green screen under tungsten my vote would be daylight/daylight but I would be interested to know if this theory works.

Shot some green screen under daylight and it was a dream to work with.

I never shoot anything tungsten on RED anymore - it's not worth the pain in post when daylight balance yields MUCH better results.

Cam

[Eki Halkka]

Comments anyone?

To me this sounds like a silly idea - tungsten lights have roughly the same color as skin, if the camera is balanced for daylight. Lighting the background with tungsten will thus reduce the separation of fore- and background.

Lighting the background with daylight, and the foreground with tungsten would make much more sense - it would increase the separation as the foreground would have an orange cast.

[Dominic Jones]

The gold standard for chromakey work with Red is to light the BG with green Kino tubes and the FG with daylight.

I can´t really see an advantage to using tungsten for the BG (other than cost and the fact that there are bigger soft sources available in tungsten, such as spacelights), but it would be intersting to do some tests. Next time I have the chance I´ll try a quick setup with the above system and see how it compares to a fully daylight system...

[Hans von Sonntag]

The gold standard for chromakey work with Red is to light the BG with green Kino tubes and the FG with daylight.

In most situations the colour amount is not the problem. Main problems are an unevenly lit screen giving uneven luma data which is bad for separtion and unwanted colour spill on the subject. Green Kinos are prone to produce spill, much more than conventional lighting source are.

For a daylight balanced sensor/filmstock lighting daylight is meaningful.

Hans

[David Mullen ASC]

Doesn't make sense to me to throw more red wavelengths at a green screen than what's hitting the subject.

[Jeff Kilgroe]

Uh... I have to agree with everyone else in regards to the tungsten / daylight setup. Also what Hans says about green Kinos is definitely something to be aware of. When lighting with a green source like that, it's easier to induce spill because of the one-color output range and how our eyes and even some light meters react, in relation to just how much green light is being reflected. It also depends on the screen material and color too. I recently shot some green screen using a white cyc lit with green Kinos. It actually worked very well.

Best advice is, when shooting a setup that is new to you, take some test shots first and tweak where you need to.

[Dominic Jones]

Totally agree the colour amount is not an issue - however, one advantage from the green Kino tubes is a narrowing of the colour range present in the light on (and from) the screen, which can be beneficial to separation in my experience. That said, I do most often shoot with standard lighting on the cyc.

Spill-wise, whilst the Kinos are a little tricky to handle sometimes, I´ve never had any problems with them, and in situations where you have got a little spill it is easier to suppress in post due to the tight wavelength spread (not that you should rely on that, of course)...

One thing that is problematic using the green tubes is lighting floors for full lengths, which obviously doesn´t work!! For what it´s worth, I shoot the majority of the GS work I do using "standard" lighting, either tungsten or daylight. But I do quite like the Kino route...

Just my 0.02, of course - ymmv.

Cheers,
Dom.

EDIT: Nice idea with the white cyc/green tubes Jeff, very cute!...

[Jeff Kilgroe]

Nice idea with the white cyc/green tubes Jeff, very cute!...

Wasn't really my idea... It was a project that was being shot in front of a white cyc. The director and client/producer decided to sneak some green screen shots in there as well. No problem, I was just going to drop a 20x20 green fabric in front of the cyc wall. I had just sent someone to go pick up my backdrop when the gaffer and director tell me they have green tubes for the Kinos. So we set it up and fire off a test shot, it worked. We were already shooting by the time my guy came back with the backdrop.

I had actually seen this done before, just had never done it myself so I was a bit unsure of what to expect. All good. I would still prefer lighting a green surface for green chromakey work, but this worked just great for a bunch of talking heads.

[SF Geek]

I noticed some people have had problems shooting green screen with the red. I don't know if they are severely underexposing the green screen or that they or their compositor are still new at pulling keys. I have lit green screen with both tungsten and daylight sources and both work great. I have lit them pretty unevenly due to time issues and still had no problems. This camera is easier than most for pulling keys. The only issue is figuring out how to get the right exposure. It's not like normal HD with a waveform monitor.