ACCURATELY READING AND BALANCING LED LIGHTS REQUIRES THE LATEST COLOR METER.
I have finally fully committed to LED lights, particularly the RGB variety.
When I first started in the business color negative film was balanced for 3200K and that was it. Shooting outside required correcting 5600K to 3200K, accomplished by inserting a Wratten #85 glass filter or gel in the light path. Shooting on stage employed lights with “continuous” full spectrum, filament based fixtures only. These ranged from 25 watt household bulbs up to large 10,000 watt units. Generally speaking, the color temperature of “practical” lamps and bare bulbs measure around 2500K and the movie lights 3200K. To warm up a movie light to match the warmth of a desk lamp we added “CTO” (color temperature orange). For a cooler or night time look we added “CTB” (color temperature blue). We still use these gels today for correction and creative applications.
The choices were simple, straightforward and around for a long time. Highly saturated party colored gels emerged in the 70’s and were popular in nightclub and hallucinogenic sequences, etc. They are still widely used today. RGB LED lights can replicate any of these gel colors electronically in addition to being able to match ANY other lighting source on set.
Provided you have the latest color meter.
Mixed colored lighting environments never bothered me much until inexpensive, fixed color LED’s arrived. The sometimes bizarre native color they exhibited was noticeable to the eye and very difficult to manually balance accurately until Sekonic introduced the C 700 color meter a few years ago. This meter was able to identify and recommend the gels needed to balance nasty color spikes inherent in cheap LED’s. If you’re in the market for new lights, don’t be seduced by the low price, study the published CRI properties of the light first and look at the spectrographic charts that the manufacturer should provide to the consumer.
An RGB LED color gamut is huge as seen in the above CIE 1931 chart. Old color meters don’t see these additional wavelengths accurately and a color meter has to, if you want a good match to other light sources.
So if you are fussy about knowing exactly what the color temperature of a light is and you need the ability to match that source to other fixtures, be prepared to spend some real money to get the latest color meter from Sekonic. Tough to swallow, but a necessary investment if you are serious about cinematography.
