April 3, 2012

How Well Do Leading LED Lights Mix With Tungsten Lighting? A Shootout Aims to Answer

LED lights present a number of advantages -- they tend to be more energy efficient, don't give off as much heat, and should (in the future) have the ability to replicate various color temperatures without the need of gels. But they also have their cons, primary of which is the difficulty in mixing them with existing tungsten lights and other incandescent lighting, and a tendency to cast a blueish tinge. With that in mind, Art Adams, over at the ProVideo Coalition blog was approached by PRG to do a LED light shootout that compared a variety of LED lights with a standard tungsten light. The results are pretty interesting for anyone interested in seeing the state of LED lighting vs tungsten:

First off, to see the results, you'll have to go to the PRG homepage, and click on the "How does it look? Compare TruColor on camera" image on the bottom left. It gives you a series of "MacBeth" charts with the upper half (I believe) representing the color under the tungsten light, and the bottom half showing the color under the given LED. They also provide a color rendering index (CRI) score.

The results? Well... not too surprisingly, PRG's TruColor Foton gets the highest CRI score. Adams points out that this was done objectively and independently, even if it was paid by PRG, and you can check out his full post for the details on how they tried to do that. Ultimately, regardless of the CRI score (which can be a problematic standard in its own right), Adams points out:

Having done some rudimentary color science work on the Kelvin Tile I can safely say that color itself is a form of witchcraft, and getting it right in an LED lamp is extraordinarily difficult. It can really only be judged in reference to something else as our brains quickly neutralize color shifts. Also, while any of these lights might be adequate on its own the game changes completely when a wonky light source is mixed with anothers. That’s when the color differences really stand out, if not by eye then on camera.

So even if most of the LED lights don't mix well with Tungsten, you may still have a pretty good light as long as you mix with other LEDs. Of course, as Adams states, testing with your own equipment is the best way to figure out how best to correct for these discrepancies.

Have any of you tried going for an all LED lighting set up? Have you found particular LED lights that mix well with existing lighting? Share below!

[via ProVideo Coalition]

Your Comment

14 Comments

I just picked up a cheap lumahawk, dimmable and Kelvin controllable on camera LED and have had good results with my preliminary testing.

April 3, 2012

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Adam J McKay

Shame PRG doesn't have a lot of form factors though. I prefer Arri's offerings (broadcaster, locaster, L7, etc). The L7 is interesting because the body itself can accept firmware updates while the LED fixture can be replaced as improvements are made.

I still think LED fixtures are a few years off since the biggest issue is sourcing properly manufactured LEDs. I absolutely love kinoflos florescence, and I'll mix them with tungsten and HMI with no issue.

April 3, 2012

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Angelo

We have been using small LED panels as light fill/kick light while shooting our short film. By using small LED panels along with a little diffusion material and a slightly colored gel, we can warm up the skin town or we can cool it down. Using LEDs is easier when you can't get a light with a dimmer, when you don't have a reflector handy, or something else.

April 4, 2012

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Kyle

Meh... Hot lights all the way. Kinos are my only exception

April 4, 2012

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I have started using an all LED kit just recently. 2 Cool Light 600's and a Rosco Axiom 6x12. All daylight. I am mixing with them 2 Lowel CaseLights, using the supplied daylight tubes. Still getting the kinks worked out but no problems so far. I did have a chance to compare a Cool Light side by side with a Lite Panel 12x12. To my eye, no difference.

April 5, 2012

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Kevin

Great article, thanks for sharing - with all the hubbub about cheap, fast, out-of-control comes with it, and LEDs are no exception! I've created a couple posts directly along these lines, I feel its an educators job not just to drone on about his or her own experience, but to help see clearly, sort out the wheat from the chaff; your posting helps with that. (http://film.cdiabu.com/)

April 5, 2012

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There is more on LED light quality in the latest publication from the European Broadcasting Union: http://tech.ebu.ch/webdav/site/tech/shared/tech-i/ebu_tech-i_011.pdf
EBU is trying to develop a way of measuring and describing the quality of LED light for TV and video use where the CRI score isn't all that usefull.

April 8, 2012

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Kåre

Thanks for share. Led Light is always a topic. Some advantages and some cons. But we all look forward to the high level development of technology.

April 11, 2012

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LED light is horrible!

Kåre, thanks for sharing that link. I saved it, particularly to show other people I work with who think that CRI is the be all and end all. I have questioned my own judgement in the past on this subject, or thought that maybe I had a faulty or lower CRI lights.

I just did a corporate video with daylight, fluorescent, and LED. This was an ENG style shoot where we didn't have time or resources to change everything to our liking.

In these situations, I've gone with the idea of getting the talent to look their best with your lights and let the backgrounds (which are out of focus and aren't of interest anyway) be fixed in post...

but the real problem is the LED's themselves. They are very unforgiving to mixed light. We were using Rosco lights, which have a CRI of...93, if I remember correctly. They don't handle gels very well (heh...even Rosco ones...). A daylight balanced LED panel with CTO often gives you Martian skin tones (green).

I'll stick to my Kinos (or tungsten). Everyone keeps touting LED's, but completely disregarding cost, efficiency, weight, lifespan, carbon footprint, I don't like the look they give me and haven't seen a single one that gives me color I like (either by eye or by monitoring).

Most brands don't publish their cycle rate, as well as their cutoff point when being underpowered. When the battery life is fading, on most LED fixtures, instead of shutting off, they will continue to operate, but their ballasts aren't cycling as fast as at full power, giving you flicker that you may or may not detect based on your own vision, the frame rate, shutter speed, amount of over or under exposure (overexposure often hides flicker), monitoring/playback systems...etc... Having to continually recharge batteries b/c you don't know if they are flickering or not, or worse, replacing alkaline batteries before they're completely dead isn't exactly eco-friendly.

According to some people on CML, Litepanels have been shown to be flicker free at high frame rates (1000fps or more)...but for most fixtures, it's still a big unknown.

I can't find it in print now, but a kinoflo ballast cycles at like 20k-30k a second (vs 50 or 60 times a second for standard household fluorescents) and that's why they're flicker-free at 150fps with any shutter angle (and shown to be flicker-free at 1000fps).

While I'm ranting, they need to up the standards for DOT certification for LED tail lights. Has anybody ever driven behind a late model Cadillac on the highway at night? It's unbearable and unsafe.

April 11, 2012

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Daniel Mimura

Really nice post and all the information are really valuable i have learn some thing about the led so thanks for sharing a wonderful blogs.

June 6, 2012

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LED lights are generally great because they are really efficient and does not develop a lot of heat. It saves me a lot from electrical power bills.

June 30, 2012

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LED Lights are the best because of low power consumptions "

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December 23, 2012

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I have a 500 LED panel light - cheapie - and I found that the only way I'm willing to use it is as a hair light to simulate daylight hitting someone from the back. It's really great for that.

January 17, 2013

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Marty

I've had terrible luck with our LED panels from Flolight - other than strength, coolness, power consumption, etc. But the color is rough - they always require gels and diffusers. Harsh.

We also had a shoot destroyed due to high speed (240fps) shots and the flicker of LED's at a ballet we shot awhile back.

I like the warmth, and sticking with the tungstens and softboxes.

July 18, 2013

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Ri