A great picture is a record of light. Whether the picture is black and white or color, it’s the light in the picture that gets put to film (or memory card). A camera is generally pretty dumb when it comes to light. It relies on some automated sensors to tell it how much light and the quality of that light, but those sensors are part of a fluid system that can be easily fooled.
We can use that system to our advantage, however, if we take the time to really scrutinize the lighting in our picture. That means looking at shadows, evaluating hotspots, determining the best direction and measure of light, and checking for color casts in the light.
One of the easiest ways to improve the color in your picture is to understand White Balance. Let’s revisit the subject now, and I’ll explain why tinkering with your White Balance is good both in and out of the camera, and why ultimately, you may not want to settle on a “proper” white balance setting. Light comes in a variety of colors. It’s not just “white”. Tungsten light bulbs, for example, are yellow/orange in color. Flourescent bulbs are somewhat green. Daylight is blue. We know this is the case because of how these types of light reflect off a white surface… and we call this color cast the color temperature of the light. The common color temperatures are often listed in a chart, which is shown below. All temperatures are measured in degrees Kelvin. Contrary to what your intuition may tell you, the higher the color temperature, the cooler the color.
Candles or oil lamps
Household light bulbs
Studio lights, photo floods
Typical daylight, most electronic flashes
Lightly overcast sky
Open shade on clear day
Heavily overcast sky
Setting Your White Balance
All digital cameras contain a sensor inside which houses not only the recording surface but also a white balance sensor. This sensor attempt to detect the color temperature you’re shooting under, and adjust the White Balance setting in your camera for it. Unfortunately, there are not always ideal circumstances for the sensor to make a good call on the White Balance, especially in situations where the light is constantly changing.
For this reason alone, it’s a good idea to set your own White Balance. Most SLR cameras have a number of pre-defined values in their menu for typical shooting scenarios… like Direct Sunlight, Shade, Incandescent (Tungsten), Flourescent, etc. More modern or advanced cameras will go even further and give you a Preset option, which let’s you measure your own particular color temperature off a neutral white or grey card. This is likely the most effective method for ensuring you get proper color, but you must make sure the card you’re measuring from is neutral in color (or rather, devoid of any color cast whatsoever). Using a regular piece of white copy paper won’t produce the desired results.
By using either a predefined White Balance or by presetting your own White Balance you’re locking your camera to a value that will not change during the course of your shooting. This means you’ll not only get accurate color, but you’ll get consistent color through the shoot. You only need to worry if you relocate to different lighting conditions, at which point you’ll want to re-evaluate your White Balance and possibly change or tweak it.
Using WhiBal Cards
The above is always good advice, but you can even go a step further with White Balance cards. These cards are now offered by a variety of manufacturers, but they are most commonly referred to as WhiBal cards. They are a set of credit-card sized cards on a ring containing neutral white, black, and one or two shades of grey.
The idea is that you or your subject hold or place the cards in the first frame of whatever you’re taking a picture of. This becomes your reference frame. It’s important to remember that this reference frame needs to be shot under the same lighting conditions as you intend to shoot hereafter… so if you’re using a flash, or studio lights, they need to fire for your reference frame.
After you’ve shot your reference frame, remove the cards and continue to shoot normally until, again, you relocate to new lighting – at which time you take a new reference frame. Most post-production photography software (such as Photoshop, Lightroom, Aperture, and higher end manufacturer software) allows you to use a white balance eyedropper tool to find areas of the photo that it can use to measure from and get proper color. Click on the white card, and you should find a neutral, proper white balance – no matter what your camera’s white balance setting was set to. This works best when shooting in RAW. Additionally, you can use the black and grey cards to measure the overall tone of the image.
Satisfying Your Eye
White Balance is subjective – and while the above might get you a technically accurate white balance, it may not be to everyone’s liking. After all, that’s why film stock like Kodachrome and Fuji Velvia sold so well back in the old days… they were oversaturated, warmed up versions of reality – which is what people seem(ed) to like. We tend to remember color much more vividly then the reality of the situation… a phenomenon called memory color. We remember that apple being bright fire-engine red, and the leaves as lime green, even if the reality wasn’t quite that vivid.
If you prefer your images a little cooler, or a little warmer, that’s your artistic choice. The best way to begin, however, is always to bring the picture to it’s most accurate starting point using the above techniques and modify it from there.