Shopping for LED lighting fixtures can be a headache. However, there a few things you can do to streamline the process and get the right gear.
Buying any new piece of filmmaking equipment is usually a fun and enjoyable process. However, at times, it can also be confusing. This is especially applicable when comparing CRI, wattage draw, and lumens vs. LUX for your lighting setup. There seems to be no standardized system between manufacturers to compare fixtures, leaving you to wonder if you’re getting the most output for your money. Let’s take a look at some considerations that should help you across the board.
Find a Foundation
The first step is to establish a baseline with which to compare all other fixtures. What I like to use is the ARRI Photometrics App. It’s a fantastic tool that gives you photometric data of all of their light fixtures. Since most of us have worked with their tungsten fresnel fixtures, they can serve as an excellent baseline to center all other lights’ performance. Plus, you will constantly see LED manufacturers tout their lights as a “1,000w hot light equivalent.” Understanding how to compare these fixtures will help you analyze the validity of these claims.
Fortunately, most LED fixtures have a photometric data sheet detailing their output at different distances. Using the ARRI Photometrics app helps you compare these distances between prospective LED fixtures and the baseline of tungsten fixtures. This way, you can decide if an LED fixture is closer to a 500w light or a 650w light.
Beam Angle
When evaluating these lights, it’s important that have similar beam angles to compare against. For example, a light at a 110-degree beam angle is not a fair comparison to a light at a 40-degree beam angle. The output will be vastly different. It’s important that you try to compare these lights under similar light quality conditions.
Fortunately, the ARRI Photometrics app allows you to adjust the beam angle of fixtures to make a fair comparison between the lighting fixtures. While you may not be able to perfectly match beam angles, you’ll be able to get close. Most LED light manufacturers will provide beam angle information on their photometric data sheet.
LUX, Lumens, and Footcandles
With no uniform system, you will find fixtures measured in LUX, lumens, and/or footcandles. Without a standardized system, you will constantly find yourself trying to figure out a way to compare lights. Fortunately, there are conversion calculators to help you in this process. A great one is featured at Suprabeam. You can use this calculator to get the accurate LUX of your light then compare that to a tungsten source.
If the light fixture you’re looking at in measured in footcandles, Google has its own calculator that can help you with this conversion by simply searching “footcandles to lux calculator.”
Conclusion
While comparing the output of light fixtures can be technical and confusing, knowing how much light fixtures actually put out is a great way to narrow your search.