Green Bulbs are strangely missing from the
White Balance Selections Choices
If you scroll down the options for White Balance in any RAW software converter you will find that there are many options. In the age of green-thinking and the prevalence of alternative-low energy light sources, you would think that photography software would be catching up. It is not-at least so far.
Example: My home is filled with Compact Fluorescent Bulbs (herein after referred to as CF). I can save energy and feel smug about my environmental awareness. None of my favorite software packages have a White Balance preset or option for dealing with images taken in predominately CF light. I tried the presets for Tungsten and for Standard Fluorescent and found the were too warm or too cool for the CF light. I set about creating a custom preset for Lightroom that I could apply repeatedly and easily. Once I have a preset, I can then port the settings for °K and Tint to any program and have a guide to get me close to start.
I started with a MacBeth ColorChecker sitting in a darkened room illuminated by a pair of CF Bulbs. I photographed it with a Canon 5D in RAW with Automatic White Balance as my setting. The RAW file was imported into Lightroom. The image above appears very warm and slightly green.
Then I applied the color space for the Canon 5D Camera Neutral in the Calibration Panel. Having profiled my cameras using the DNG Color Profiler software last week, I have a preset made to perform a camera-specific color profile application. As you can see my two 5Ds have individual profiles identified by the last three digits of their serial numbers, so that I can dial in each camera’s color accuracy individually. The resulting camera correction is applied in the image you see below.
RAW File with the Canon 5D Color Profile Applied
The difference between the files isn’t dramatic but I want to be certain that I have eliminated as many color variables as possible. I now have several Neutral Targets that I can sample with the White Balance Eye Dropper Sample Tool in Lightroom. The values varied slightly over the gamut of grayscale at the bottom of the ColorChecker but were very close. Temperature ranged from 2750-2850 and the Tint ranged from +8 to +12. The three grays immediately below white were almost identical so that was chosen to be the standard. Below is the result of the WB correction. 2800° K and Tint of +11 was the final verdict.
As you can see, this result is far better than the originals and can be applied via preset to a host of images at once. Fluorescent and Tungsten are close but not quite there. Fluorescent misses badly and tungsten shows some cast in the darker tones-especially the dark gray next to black.
Now bulbs vary by manufacturer and type so your mileage may vary. Bulbs also change with time so you will see slight variations. If you don’t know the color temperature of the bulbs under which you are exposing, you have a means to find that with a simple color checker. If you would like, I have made my preset available for download from my website located at www.fleetingglimpse.com. The preset is available by clicking on the icon below, downloading the file and placing it in your Develop module presets folder for Lightroom. Or, if you use ACR, Photo-Paint or some other software package, you can enter the values listed above into your RAW converter.
In the future, let us hope that more presets are available native for the software for the new types of lighting which emerge. What should I tackle next? LED? Perhaps.
Email me and let me know how things are going with the preset.
Rikk Flohr © 2008