In the movie production industry, LEDs are viable alternatives for tungsten lights. The modern fixtures are cheaper and require less maintenance. When it comes to energy requirements, LEDs consume very little energy, allowing operators to use the luminaries along with other power-hungry equipment. For remote sets, LEDs offer portability through battery-powered variants. During filming, the units create soft lighting features, similar to softboxes. This makes the lamps ideal for shots involving face-to-face interviews and news-related recordings. For sets that incorporate multiple lighting configurations, LEDs may also be useful, due to their instant toggling features.
Before the rise of LEDs in movie sets, most producers relied on Hydrargyrum Medium-arc Iodide (HMI) lamps. In the filming sector, LEDs are often compared with HMIs, because they are the industry standard for lighting. To date, the luminaries are still the standard in Hollywood, due to their powerful lighting capabilities. A single 150-watt HMI bulb can accomplish the same amount of power as a set of LED light panels. Based on power alone, HMIs have a clear advantage over LEDs. However, HMI technology lacks several key features that fast-paced producers are looking for, such as instant toggling. Before reaching full light output, HMIs must be warmed up for about 10 minutes. Furthermore, when moving the lights to another location or turning them off, they must also be cooled down.
HMI fixtures do exceptionally well in large movie sets, while LEDs are superior lighting options for small settings. From a cost perspective, HMIs are staggeringly expensive. This has forced some low budget production houses to focus on less expensive, but reliable lighting options, such as LEDs. Currently, movie sets rely on a range of lighting technologies for illumination. Fixtures are commonly applied according to their lighting characteristics in order to get the most out of their features. With that in mind, there is no “one-size-fits-all” solution to movie set lighting. However, this does not mean that LEDs are unsuitable replacements for other lighting technologies. This is because most traditional luminaries have reached a “ceiling” in their development. By comparison, scientists have barely scratched the surface of LED technology. Because of this, LEDs may one day outshine HMIs in movie sets.
Interestingly, the widespread adoption of LEDs for outdoor lighting systems on streets, buildings and monuments has indirectly affected the filming industry. Before the rise of LEDs, city lights incorporated older lighting technologies with warm, yellowish color temperature ratings, such as incandescent or sodium-vapor lamps. Most movies during the 90s and before that era captured city scenes that incorporated such lighting features. But these days, more and more cities are switching to LEDs with high color temperature ratings, which appears whiter, compared to its outdated predecessor.
An example of this issue comes from the movie Collateral. The movie was filmed in Los Angeles before the city started switching over to LEDs. Now, due to the distinct qualities of the city’s old lighting systems, producers are required to portray the location on film with outdated lighting technology (for scenes referencing time periods before the switch). Los Angeles made the switch in 2012 through one of the largest LED street light replacement programs in the world. Workers replaced a whopping 141,089 street lights during the first phase of the project. Officials are currently saving up to $7 million in energy costs and up to $2.5 million in maintenance costs, as a result from upgrading the street fixtures.
Buying LEDs for filming is not the same as purchasing lights for one’s home or office. There are several features that must be taken into consideration during the process, such as beam patterns, controls and Color Rendering Index (CRI) ratings. When it comes to CRI levels, or the measurement (based on a scale from 0 to 100) of a fixture’s accuracy compared to a referenced or natural light source, cinemas typically incorporate units with 90 or higher CRI ratings and/or TV Light Color Index (TLCI) ratings of 85 or better, in order to get away with as little color correction as possible. High quality LEDs can reach such desired CRI and TLCI ratings with minimal effort. Low quality variants may produce inconsistent colors, which can easily be picked up by high-powered studio cameras and industrial recording devices.
LEDs emit light differently compared to traditional luminaries on movie sets. For example, high-intensity discharge (HID) lamps emit light from a suspended light source (the arc), allowing operators to manipulate the beams using conventional tools. Such methods are usually ineffective for LEDs, because they generate light from a chip. Hence, when buying LEDs for filming, one also needs to take optical accessories and modifiers into consideration.
Lastly, like other fixtures on a movie set, LEDs must be able to handle fine-tuning and standard controls. It is common practice to use Pulse Width Modulation (PWM) protocols to boost or decrease light output. Unfortunately, this technique is not suitable for movie sets because it can cause flickering due to conflicting sample rates from nearby recording devices. A solution to this issue involves a combination of analog and PWM methods. The reason for the merge is because LEDs controlled using analog techniques are prone to color shifting when power hits below 50 percent (this phenomenon does not occur with PWM).