The Problem with Available Light
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Posted by Steve
Here’s an overlooked issue I encounter on a regular basis. I’m asked to spec out a location video shoot in a conference room or typical academic setting. After a site visit and discussion of the overall needs, it’s time to quantify the equipment, labor, and any other costs it will take to produce the finished product. My equipment consists of three general categories. Cameras and related video gear, Audio gear, and Lighting equipment. Since this is simply documentation of a live event in a well-lit room, lighting equipment is surely unnecessary, right? I used to think so, especially considering that until recently the alternative meant bringing in bulky, and very hot, potentially dangerous gear into the space, changing the look and feel of the place, all while hoping the circuit breakers wouldn’t blow. That was out of the question. But back to the question–why bring in lights when a space is plenty well lit? The answer has to do with several shortcomings with commercial lighting as it applies to video and image-making generally.
- The direction of the light. In commercially lighting, the direction is either downward or omni-directional. Downward light is generally unflattering and can produce unsightly shadows; omnidirectional lighting leads to shortcoming number 2.
- The distribution of the light. When the subject, background, and all objects in view are equally lit, the 2-dimensional video image appears very flat and dull.
- The quality of light. Lighting literally colors our emotions like nothing else. Variations in the color temperatures of daylight and mixed commercial lighting can be well accounted for through careful white balancing, but ultimately the color distribution of wavelengths of the light source determines whether the video image appears vivid and colorful, or dull and muted. Simply put, objects only “have color” if the right wavelengths of light are present to reflect off the object. You may have seen demonstrations of this where fruits in a bowl can selectively be turned gray by changing the light. Anyway, the Color Rendering Index, or CRI, is a measure of this wavelength distribution. Most commercial lighting is not designed with this in mind, so it tends to have a low CRI. Good professional video lights have a high CRI, and the difference is dramatic.
- The amount of light. Okay, I said we’d assume that the room was plenty bright, right? But more often than not, the room is darkened at some point to use a multimedia projector. So having that bit of supplemental lighting on the subject that helps highlight the subject from the background as we did in number 2 above, might now be the only light source keeping the subject from retreating into silhouette or total darkness. Remember that the camera must iris down to show the brighter projected images, so the darkening of the surrounding room and person speaking is much more pronounced on video that to our naked eyes.
No single one of the shortcomings of using available commercial lighting that I’ve described above really rises to the level of being a deal-breaker as far as being able to record acceptable video, especially for most academic purposes. But when I consider their combined effects, and reflect upon my own experiences, it’s become clear that just using whatever lighting is available by default is often one of the biggest factors limiting the production value of the resulting video.
I know better than to expect perfection, especially with assignments like these in uncontrolled environments. But as a committed professional, I must aim for something better than just “acceptable”. And now that more and more of this casual and unofficial sort of content is distributed so widely via the web, academic and other institutions see the need to protect and promote their brand with an eye toward higher standards of production value in their media. So the purpose may be more than just academic.
Solutions: Cheaper and easier than you’d think.
I made mention earlier of the bad old days of lighting gear so hot you could cook with it. Then came the compact fluorescent era, which was a big improvement. I still use some of those, but their best application is for throwing soft, diffuse light a short distance. This works very well for interview lighting. But what is needed for on-location presentations is something bright enough to throw a medium distance of typically between 10 and 30 feet so it can be out of the way, and yet have a soft enough beam to not appear harsh or too obtrusive to the presenter or the audience.
The newest generation of LED lights fit all of these criteria. So I am currently in the process of pairing different LED light sources in different fixtures and configurations to have a variety lights to supplement and improve the video image for various presentations.
I hope to follow up this post with a video on the same subject. It would be very interesting (for me anyway!) to show examples of everything I’ve mentioned, but at the very least I plan to demonstrate some of this new lighting gear and how it may provide solutions and improvements to your next video presentation.