blog by

rob kircher

Friday, June 25, 2010

Shooting in the Theater… White Balance revisited

So it’s been a long time since I’ve discussed anything regarding theater photography but I happened to run into an interesting situation when shooting Alice.

First lets review our last conversation on this subject of WB in the theater.  In short we determined that setting the camera’s WB to around 3200K best matched the traditional tungsten theater lights.   This setting will best represent all the different colors used to accent the set and actors. 

Lets also briefly clear up a common misconception I hear from other photographers when discussing WB.  The particular gel color on theater lights should NOT determine your WB settings.  As a mater of fact, quite the opposite.  Setting the WB to that of a gelled light will do nothing but obliterate that color and throw everything else off.  If we are to represent the colors correctly we must set the camera to the WB of an un-gelled (white) light. 

Now with the house keeping expended, enter a new challenge…

The LED light. 

That’s right, just when we get the Tungsten light all figured out, the theater world tosses in the LED fixture.  It actually makes a lot of sense economically.  An LED element burns for many many more hours than a traditional tungsten element.  They use less electricity, and they are now just as intense and the traditional fixture.  The one cool advantage they have over traditional lights is you can run the LED element in an RGB series and produce just about any color you want with out the need for gels.  In addition, you can gradually fade from one color to the next removing the need for noisy gel rollers that can’t fade anyway.  Way cool. 

For these very reasons, LEDs are taking over the theater world but along with them comes a slue of photographic problems one of which is color temperature.  LEDs can have a color temp as high as 8600K which will play havoc with your photographs when dealing with a mix of traditional and LED fixtures.  Worse yet, I haven’t found any consistency between manufactures.  Pulling the specs on several of the larger providers shows a large range of WB numbers between manufactures.  Additionally, only a very few actually allow you to set the WB for the LED through the DMX controller.  That’s right, SET the WB of the light.  According to the manufactures specs, some allow you to set the temperature of pure white to a number that matches the rest of you lighting.   Problem is, most LD (Lighting Designers) won’t bother as the human eye doesn’t have the same problems our cameras have when interpreting color.  The LD is just going to set the light to the color that looks right and be done with it.  The fact that its based on a WB of 8500K instead of 3200K doesn’t mater to the LD near as much as it maters to the photographer. 

As an example, look at the following photo.  The first version is processed at 3300K matching the WB of the tungsten lights.  Notice the green on the fabric drops behind the Mad Hatter.  The green is pale and dull.  Note the blue drop just behind Alice.  See the very little bit of green just evident behind Alice?    

20100222 Alice-0226Image processed at 3300K to match traditional tungsten lights 

Now look at this version of the same image processed at 5600K, the temp of the LEDs used to light the drops.

20100222 Alice-0226-001Image processed at 5600k to match the LED lights used to light the drops 

Notice how much better the green looks and just how much green was lost in the drop behind Alice in the previous example.  There’s a huge difference!!! But also look at how far off the color is especially with the actors skin tones.  Yuck, way too orange.  Of course, this is because the actors and table were lit with traditional tungsten lighting. 

So what is one to do?  Well the very first thing to do is talk to the LD and find out what fixtures are being used in the production.  If you find that its a mix, then you need to hope the LD understands the problem and has compensated for it and/or hope you can find a good balance in post processing.  The key is to find out what the primary lighting device is and set the camera to that temperature.  Take a few test shots and adjust your WB setting to see if you can find a compromise setting that will work in camera.  Short of that, your at the mercy of the LD and the camera. 

At some point I suspect that tungsten will be replace with LED or something similar but until that happens we’ll have to deal with this mix of light.  It’s going to be a real challenge but I hope the information here at least help explain why some of the colors in your photos just don’t seem right and how to adjust when needed.