Gray Card Photography Basics
A gray card is a flat, gray reference object used to neutralize color in your photographs. The card is a shade that is called 18% gray. If I tried to explain what 18% gray means, your eyes would glaze over. (It has to do with a flat reflectance spectrum. If you know what that means, call me so I can offer you a job.)
All digital cameras, from point-and-shoots to DSLRs allow you to change the white balance in your photos. Depending on the light source surrounding the subject you’re shooting, your picture can turn out looking too warm or too cool. For instance, tungsten light (the light emitted from the lamps in your home) will cast an orange tone over your photos, while “shade” (very indirect sunlight) will make your pictures appear more on the blue side.
Gray Card White Balance
You can set your White Balance setting to be on “Auto White Balance” or “AWB” which means your camera will adjust the white balance for you. Alternately, you can manually select the kind of light source you’re shooting in, whether it’s tungsten, fluorescent, or direct light from the sun. But sometimes a scene can be somewhat complex. What if there is more than one kind of lighting source? This is where the gray card comes in.
If you have a more advanced level camera, the gray card will allow you set a custom white balance based on the exact combination of lighting sources that are lighting up your subject. Using the gray card will allow you to create a custom white balance setting. (Not all cameras have a custom white balance option so you’ll have to check if your camera does or not.) The rules to using a gray card may seem a little complex at first, but once mastered, it can become second nature. First, you must take a photo of the card in the same lighting as your subject (yes, you’ll be taking a photo of a piece of paper, basically). Set your white balance setting to “Custom” (if your camera offers the option) and then your camera will allow you to select the photo you just took of the gray card as the reference point.
Is Gray Card Photography Necessary?
But here’s the real question: do you really need a gray card? The short answer is: Not really. When it comes down to it, your camera does a GREAT job deciding the white balance for you. Practically speaking, only professional photographers use gray cards and only professional photographers in certain genres of photography. A studio photographer is much more likely to use a gray card than, say, a wedding photographer.
While they aren’t outrageously pricey (depending on the brand and quantity, they can range from around $3 to $30), they can be a bit of a hassle. In the time it takes you to dig that card out of your bag and set up your custom white balance, your opportunity to take the perfect shot may have passed.
The white balance selections on your camera may not be 100% accurate, but they can get pretty dang close. If you’re more of a hobby photographer, bypass the gray card. It’ll just slow you down. If you’re a perfectionist with how your images look, you can play around with a gray card if you’d like, but chances are you’ll prefer the handy white balance selections your camera offers.