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LED lights theory - CRI x TLCI x GAI


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#1 Jan Valis

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Posted 16 April 2018 - 06:12 PM

Hello, I am writing a dissertation work on LEDs and came across a thing I don't quite understand. I do understand why there are differences between CRIs, TLCI and CQS. While looking at different ratings of different lights in Etudes sur les projecteurs á LED by CST, I saw lamps with great CRI and TLCI values, but with quite bad Gamut Area index, being way below the optimum (like 65-75 of 95). Why is this? Is it an important piece of information? Also, which of the color rendering parametres would you say is the most important for image quality?

Thank you,

Jan Vališ - Student of cinematography


Edited by Jan Valis, 16 April 2018 - 06:14 PM.

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#2 Guy Holt

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Posted 16 April 2018 - 08:14 PM

... which of the color rendering parametres would you say is the most important for image quality?

 

CRI is not the best indicator to judge the color rendering capability of LED fixtures because it is a measurement that can be messaged by manufacturers to give high readings without giving good results. For a more accurate assessment of the color rendering capability of LED fixtures see The Academy of Motion Picture Arts and Sciences'  “Solid State Lighting Technical Assessment" - a research project in which they systematically tested and compared  the LED technology available  at the time to Incandescent and HMI light sources. On their website they have posted not only side by side comparisons of chip charts exposed under each light source but also set pieces, wardrobe, and make-up. To maintain neutrality, no brand names are mentioned in their results, but they chose lights that reflect the various approaches taken by the major manufacturers of LED fixtures for motion picture applications. You can find a link to the Academy of Motion Picture Arts and Sciences’ “Solid State Lighting Project Technical Assessment", as well as other information regarding Mole  & Litepanel LEDS on our website at http://www.screenlig...generators.html.

 

Guy Holt, Gaffer

ScreenLight & Grip

Lighting Rental & Sales in Boston


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Rig Wheels Passport

Paralinx LLC

rebotnix Technologies

Tai Audio

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