I have had this argument with colleagues countless times and it looks like I will finally get a bit of retribution on the issue. Though LED and Tungsten are not the only two types of lighting units employed in film and video production (HMIs and Fluorescents being the other two big contenders), there has been a huge push by manufacturers of late to bring LED technology to the forefront as a major player, possibly even as an alternative to the tungsten arsenal.
The proponents of LEDs, or light emitting diodes, will generally argue one or a combination of several points heavily: temperature, weight and ease of use. There is no argument that LEDs are a much cooler alternative to a tungsten light. In fact, there is hardly any heat at all from these instruments, even after extended use. Also, because the units are just a panel of light emitting diodes arranged in vertical and horizontal grids, these instruments tend to be lighter, more ergonomic and easier to transport. The last cornerstone of the pro LED faction is the ease of use, as many of these instruments have not only built-in abilities to dim the emitted light, but also color temperature controls as well. In theory LEDs seem like a no brainer, don’t they? If you took these arguments at face value, then sure it would be; however, if you delve a little deeper into the makeup of light, vision and how cameras read the color spectrum, then it’s not such an easy sale.
I have always been a strong supporter of the other side of the coin. Unless I have to, I rarely use anything outside of tungsten or HMI instruments, with LEDs being my last choice, even below fluorescents tube technology instruments like Kino-Flos. Tungsten instruments have been industry standard since nearly the beginning of motion picture artificial lighting use over 80 years ago. Tungsten lights work by heating a filament of tungsten in a halogen gas encased tube to temperatures hot enough to glow. Being a continuous source, these instruments have an arc that creates a very consistent, clean looking stream of visible light both to the eye and through the lens of a camera. Because these lights are heating the filament to extreme temperatures, they do get hot, and yes, the housing to contain the lamps has to be built in such a way that the lighting instrument isn’t dangerous to use, which more times than not can make these units big and bulky for the amount of output they produce. All of these physical properties do have their disadvantages, but the one point that can’t be argued is that tungsten instruments produce a very pleasurable light for film and video production.
To illustrate the point, here is a video from the Academy of Motion Picture Arts and Sciences that explains some of the correlations between film emulsions and color, and the relative shortcomings of LED units in today’s productions. Further results of their extensive studies on the subject are available on the Academy’s Web site at: http://www.oscars.org/science-technology/council/projects/ssl/index.html.
Though it didn’t take a multi-million dollar study by the Academy to convince me that I’d go with a 40-year-old Tweenie over a brand new LED, it does feel good to have some deeply scientific research on hand to help prove my point to detractors. I will admit that LED technology is an interesting and potentially wonderful tool for filmmakers, but err on the side of caution that this technology is not quite where it needs to be yet to fully incorporate into production workflows on set, unless of course you are going for a specific look that these inferior discontinuous instruments produce. In that case, I guess you are creating art.