Eric Hamilton – Celebrity / DJ / Nightlife Photographer

I make my living designing lighting for live events and architectural installation, but I love photography, and use the medium as a means of exploring lighting tools and techniques. I recently explored using RGB LED as the only light source for a photoshoot and got some surprising results. I had had some success using the Altman Spectra Par series of fixtures on some live events and since I had them on hand for an extra day or so I decided to experiment. I shoot with a Nikon D70, for those playing at home.

The benefits to these sources are obvious, if you’re looking for dynamic, rapid color changing you can’t beat this technology. One push of the slider and your red light is purple, or bright blue, or teal or orange or…you get the idea. But like any other tool, there is a trade off, in this case two. The first, they are not as bright as advertised, and second, more importantly, “white” light is tough to achieve.

First on brightness, in fairness, I didn’t even look at the footcandle data before I set up. I lit a faux brick wall for an event ceremony with the fixtures I had around and there was plenty of light to my eye, so I figured the lens would see things the same way. I was wrong. My 18mm-50mm adjustable lens was wide open at f3.5 and I found my shutters unbearably slow. My ISO had to drop to a disappointing 800 (you can really pick up noise on the D70 at 800 and above), at that ISO I was shooting with a shutter at 1/50 which for posed action was acceptable, if not ideal.

The next issue was white balance. The D70 like most DSLR allows custom WB. I won’t go into the procedure for setting it, as you know your camera if you’re reading this blog, here’s what you need to know about RGB LED and your sensor. Every camera is different and will experience color differently but RGB LED wash lights tend to have similar properties. A circuit board with an array of Red, Green and Blue LEDs emits light against a lens, the lens is designed to mix the light and project a smooth color. Mixing the intensities of Red, Green, and Blue (the primary colors of light) will create an incredible array of colors, and in theory these three colors, mixed in perfect balance will give you “white.” This, of course, is not the case in the real world. Without getting into the weeds on LED technology basically blue LED is brighter than warmer colors, this is due to limitations in phospor technology and flaws in the engineering of the fixture. To be fair, this generation of Spectra par was never meant for what I was using it for. This was an experiment after all.

So I ran the fixture to full and pointed it at a white card, and even to my eye the color was very cool. I didn’t have a light meter with a kelvin gauge, but by eye anywhere from 5600k to 6000k is a conservative estimate for the temperature coming out of these bad boys. I shot several test cards and still was seeing blue-ish results in test photos. I focused a second fixture on the white card and this time backed the blue off 10% this got be a little closer to where I wanted to be. Slightly cool, but acceptable.

I didn’t have all that much time to perfect my strategy anyway as the models were beginning to arrive. The Spectra Pars have 3 lenses a narrow , medium, and wide flood. I had six fixtures so I opted to use 2 in each beam spread, my thought was that 2 would act as key lights, 2 fill and 2 highlight. In general, this strategy worked pretty well. It amazed me how much better the white balance got the more sources were used in the setup. In the early shots it was hard to avoid super saturation, but as the shoot wore on I learned that I needed 2 or 3 heads set to “white” with the rest as a color fill if I didn’t want over-the-top color.

All of the photos in the post are from this shoot. As you can see, some are more over the top color wise, but I was able to get pretty true whites. None of these images have color-correction done in post, just cropping, and of course they are saved for the web so we’re losing resolution and color information in these versions. All those caveats, you get a sense for what is possible with RGB LED. A few take-aways:

Give yourself time to adjust in-camera white balance.

Be wary of mixing these with another source on your subject. That’s not to say it can’t be done, but too many “whites” might be hard to prepare for.

Work with a theatrical lighting supplier when renting these. Explain what you want to accomplish, not only will they point you to the best gear, they can find you a cheap and easy-to-setup control solution.

Have more questions? Have you tried this before? The comment section awaits.

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