Wikipedia on CRI light spectrum

[Danno Anderson]

[h=2]Film and video high-CRI LED lighting incompatibility[/h]Problems have been encountered attempting to use otherwise high CRI LED lighting on film and video sets. The color spectra of LED lighting primary colors does not match the expected color wavelength bandpasses of film emulsions and digital sensors. As a result, color rendition can be completely unpredictable in optical prints, transfers to digital media from film (DI's), and video camera recordings. This phenomenon with respect to motion picture film has been documented in an LED lighting evaluation series of tests produced by the Academy of Motion Picture Arts and Sciences scientific staff.[SUP][30]
[TABLE="class: wikitable, width: 1"]
[TR]
[TH="bgcolor: #F2F2F2, align: center"]Light source[/TH]
[TH="bgcolor: #F2F2F2, align: center"]CCT (K)[/TH]
[TH="bgcolor: #F2F2F2, align: center"]CRI[/TH]
[/TR]
[TR]
[TD]Low-pressure sodium (LPS/SOX)[/TD]
[TD]1800[/TD]
[TD]~5[/TD]
[/TR]
[TR]
[TD]Clear mercury-vapor[/TD]
[TD]6410[/TD]
[TD]17[/TD]
[/TR]
[TR]
[TD]High-pressure sodium (HPS/SON)[/TD]
[TD]2100[/TD]
[TD]24[/TD]
[/TR]
[TR]
[TD]Coated mercury-vapor[/TD]
[TD]3600[/TD]
[TD]49[/TD]
[/TR]
[TR]
[TD]Halophosphate warm-white fluorescent[/TD]
[TD]2940[/TD]
[TD]51[/TD]
[/TR]
[TR]
[TD]Halophosphate cool-white fluorescent[/TD]
[TD]4230[/TD]
[TD]64[/TD]
[/TR]
[TR]
[TD]Tri-phosphor warm-white fluorescent[/TD]
[TD]2940[/TD]
[TD]73[/TD]
[/TR]
[TR]
[TD]Halophosphate cool-daylight fluorescent[/TD]
[TD]6430[/TD]
[TD]76[/TD]
[/TR]
[TR]
[TD]"White" SON[/TD]
[TD]2700[/TD]
[TD]82[/TD]
[/TR]
[TR]
[TD]Quartz metal halide[/TD]
[TD]4200[/TD]
[TD]85[/TD]
[/TR]
[TR]
[TD]Tri-phosphor cool-white fluorescent[/TD]
[TD]4080[/TD]
[TD]89[/TD]
[/TR]
[TR]
[TD]Ceramic metal halide[/TD]
[TD]5400[/TD]
[TD]96[/TD]
[/TR]
[TR]
[TD]Incandescent/halogen bulb[/TD]
[TD]3200[/TD]
[TD]100[/TD]
[/TR]
[/TABLE]
http://en.wikipedia.org/wiki/Color_rendering_index

[/SUP]

 

[Jason Comparetto]

Of course I understand the concept and somewhat the calculation, but doesn't this whole CRI system seem overly simplified for our line of work? I could be wrong, after all I don't fully understand the CRI formula 100%.

 

[Danno Anderson]

What I get out of the article is that using high wattage incandescent light will reduce color problems as much as possible. I don't claim to know much about though. The article articles different points of view, which is nice.

 

[Charlie Hohenshilt]

The [30] reference on the wiki page links to The Academy of Motion Picture Arts and Sciences page. On the right are some Symposium Videos. The first group are about the science of light and color. It also goes into detail of CRI and why it is important. The videos of makeup thru props show that non-consistent light sources give varying colors.

 

[PatrickFaith]

The [30] reference on the wiki page links to The Academy of Motion Picture Arts and Sciences page. On the right are some Symposium Videos. The first group are about the science of light and color. It also goes into detail of CRI and why it is important. The videos of makeup thru props show that non-consistent light sources give varying colors.

Thank you ... Great info ... i was hoping to find something like that (from the Academy), and how it overlapped with the mysterium-x sensor. So far I haven't seen any answers to what I thought was a basic question of led to mysterium-x sensor alignment ( http://www.reduser.net/forum/showthread.php?69284-MYSTERIUM-X-Spectrum-and-LED-Lighting )
I have been debating mixing LED with Studio Tungsten, but I really need to know how the epic/scarlet sensor lines up. I really like the flexibility of LED, specially for the low budget feature film shooting I'm doing ... since I'm often in limited sized sets, inadequate cooling, and power that isn't great.

 

[paulherrin]

that wikipedia article is like approaching a matrix screen...

can anyone concisely explain this whole deal with LED lighting? i.e. pros/cons - i don't know anything about led lighting...

 

[PatrickFaith]

that wikipedia article is like approaching a matrix screen...
can anyone concisely explain this whole deal with LED lighting? i.e. pros/cons - i don't know anything about led lighting...

on the link http://www.oscars.org/science-technology/council/projects/ssl/index.html ... if you click on the movie which is on the right side "Emulsion and Color" ... a total expert explains it fairly clearly.

Long story short though ... is LED's have very narrow/squigly emission bands compared to normal lights (like tungston), also the sensor in the camera can have bands which don't reflect how traditional film camera's work ... so you can get all sort of wierd non-correctable color shifts when you use LED lighting (especially for feature film). Lot of the problems are with skin tone, which is even worse. The Academy is doing a professional study ... which Charlie Hohenshilt referenced (LED light is great because of the power, but these color shift issues might not be correctable). The "makeup case" video is very telling ... I'm about to give up on LED's, even though i love using them.