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By Sara Frances, M.Photog.CR

When you have the best tools close to hand you’re more likely to use them. Consistent use of those tools to achieve exposure accuracy determines literally everything we can do with a digital image. Dressing for success in a suit jacket has the added benefit of an inside pocket for one of the most valuable little tools you can own, namely an ExpoDisc or Ed Pierce white balance target.

How many times do we need to be told that exposure is not just shutter speed and f-stop but, even more important, white balance? Reminders may be annoying, but I know absolutely that if I don’t take the extra time to evaluate each new lighting situation, I will pay later with mediocre quality and sometimes serious correction problems. The complexity and quantity of settings required to perfect digital capture are admittedly hard to keep track of in a controlled shoot—mind-boggling in the fast pace of location events. It’s understandable why automatic settings that are responsible for the current shallow ease of entry into commercial photography also falsely lure the professional seeking to mitigate her workload on site.

Relentless attention to white balance, even before exposure, will produce camera accuracy, which in turn pays real money dividends in print or album production. Careful white balance will lower your costs and time if you correct in Photoshop yourself. Whether you print on your own inkjet printer as I do, or have a laboratory color correct and print for you, you’ll achieve far better color and continuity.

The keys to the very best capture are right there for the reading in the Photoshop Camera Raw conversion screen. It took me more than a year of using the raw converter before the light bulb came on. Why doesn’t anybody just tell us that raw has the artistic power of Ansel Adams’ chemical darkroom, his famous Zone System? Raw conversion is digital darkroom for adults—and so much easier!

An in-depth look at the organization of the Photoshop Camera Raw interface actually leads us through the Zone System steps, and in the process reveals one of the most important secrets of good camera capture.

What’s the first thing you see in the adjustment sliders? White balance.

After years of correcting each and every exposure I’ve made as well as those of my event team and lots of students, I have found that white balance is the most important characteristic of the original file. It’s also the very first adjustment that should be made in Photoshop, assuming that the exposure is somewhere close to accurate.  

The real shocker I've discovered is that, contrary to popular belief, you actually can’t “fix everything in post.” Raw files, though far more robust and editable than JPEG, are not fully color correctible without consequences. (Note that JPEGS with really poor color are a total nightmare to correct in comparison to merely difficult in raw.) The evidence of potential file degradation during the optimization process is empirically verifiable just by watching the histogram change in the raw converter window.

Changing the white balance can and does darken or lighten the effective exposure of a file, thus potentially degrading shadow and highlight areas and the appearance of noise. When correcting cooler, bluer overall capture, the effective exposure increases. When an overly yellow image must be neutralized, the change is often noticeably negative.

Here’s a bit more technical examination of the Photoshop Camera Raw, which offers just two sliders for color balance, rather than three, which you might expect, considering the RGB histogram window. The name of the first slider helps. Temperature in photography refers to kelvin, and that slider moves predictably from cool blue to warm yellow. Tint is Photoshop’s name for the green to magenta axis of color space.

I queried the late Bruce Fraser, who replied that the Temperature slider actually approximates teal to orange, not just blue to yellow, and Tint is really more like chartreuse to purple. You can prove this for yourself by taking an image with mostly pale white tones and moving the sliders to the extreme ends. He further called my attention to how Temperature and Tint are roughly equivalent to the B and A channels of LAB color space that many advanced Photoshop users advocate for the most accurate color correction. This is an easy correlation to the way labs print color film, even if we don’t understand the fine points. Yellow and magenta filtration are used almost exclusively, cyan only rarely for extreme corrections. So perhaps color balance in film and digital are not so different after all.

Keeping on top of white balance is most difficult in a non-controlled environment. Overly warm location light and sometimes abominable mixed light are the ubiquitous challenges faced by wedding, event and portrait photographers. Scene-to-scene fluctuation in the color, intensity, type and direction of light on location has never been easy; digital just made it more critical.

Professional fashion models are used to the stop and start scenario when the photographer stops shooting to re-meter or re-balance the color, but wedding party subjects may quickly lose spirt, expression and momentum with technical interruptions.

In situations like the one pictured below, I prefer to use a judicious touch of strobe, often bounced, to stop action, augment ambient light and give a more pleasing dimensional appearance. I also drag the shutter to eliminate the amateur “black hole” background. The effect is striking, but without custom or kelvin white balance setting, the capture tonal bias can be as yellow as daylight film exposed at slow shutter speed in a tungsten-lit church.

Open such an image, which may also be quite dark due to the very nature of events and event spaces, start correcting the yellow with the temperature slider, and watch the histogram slip to the left. The image becomes more neutral, but the effective exposure has dropped dramatically. The inevitable conclusion is that color balance is the unexpected but very necessary “fourth for bridge”—you absolutely cannot do without. Color balance completes the 4-way party of ISO equivalent, shutter speed and f-stop.

This series of images demonstrates how overly yellow capture due to improper white balance setting adversely affects exposure levels. The dark hall with mixed lighting dictated using high ISO 1600, 35mm lens, with the shutter drag exposure of 1/50 second at f/2.8, slight fill-flash with auto white balance on ETTL with a Gary Fong Whale Tail, front closed, in place.

Once the image is examined in Photoshop Camera Raw, the generally satisfactory capture seems too warm. The histograms shown are as shot (top), corrected for white balance alone (above) and the final optimized image (below).

Ignoring the exposure spikes from the spotlights, look at the arrows, which show how neutralizing yellow actually darkens the exposure, and also compresses the range of midtones. The next step of lightening the exposure overall is an effective rise in the ISO, already high due to the circumstances. Midtones, which are usually the most relevant for people subjects, have been stretched for greater separation by Zone System style manipulation: the contrast is lowered and the mid-point elevated with the Brightness slider. Increased noise and less sharpness were seen in the Converter screen following this correction, necessitating adjustment in the Details Tab for both Luminance and Chromenance Noise.

Professional dancers are Orialis Serrano and Raymon V. Ashley.
Images ©Sara Frances.