Ever notice how there is a color shift in your photos? This is really annoying when you need to achieve perfect skin tones, or accurate color in food or flowers.
Digital cameras have different selections for white balance. Automatic, Sunny, Shady, Cloudy, Tungsten, Fluorescent, Flash, Custom, and Kelvin. Most of the time using the appropriate setting is adequate, but there are certain situations where the camera just can’t read the light correctly. For instance, skin tones should be spot on for portrait photography. You don’t want your model’s skin to appear too orange or too red. Another example is how a digital camera tries to read shades of purple and blues in flowers. Using the camera’s white balance settings does not get the right shade in an iris. No matter which white balance setting I use, it always looks too blue or too pink instead of purple.
When I need to get a perfect white balance, I use an ExpoDisc. This is a device that perfectly measures the temperature of light coming into your camera. It is a round “filter” tool that fits on the front of your lens. You take a shot with the ExpoDisc attached, and it records the incident light to provide an accurate reading. Incident light is the light that falls directly on a subject.
Take a close look at the two flower photos. Notice how the top flower has more pure red tones in it than the bottom flower? The top flower was photographed with an ExpoDisc and a Custom White Balance setting. The color is exactly the same as the flower appears in real life. Now compare the bottom photo. It was shot with the camera’s Auto White Balance setting. See how much bluer the hue is? The camera was making it’s best guess at white balance, but lost the beautiful vivid reds, and replaced them with bluer tones.
Here’s how you set a custom white balance with the ExpoDisc. I will give instructions for a Canon 5D. If you have a different camera, refer to your camera’s manual to find the settings.
1. Press your white balance selector to choose the Custom Setting. With a Canon 5D, you press the WB button, then roll your Quick Control dial (the large wheel on the back of your camera) to select the Custom White Balance icon. It looks this:
2. Place your ExpoDisc over your lens. If your lens has Auto and Manual focus, set it to Manual. If you try to take the photo using Auto focus, it won’t work. The camera cannot read a focus because there is nothing for it to focus on when the ExpoDisc is in place. This is what the ExpoDisc looks like on your lens.
3. Walk over to your subject and point the camera towards where you will be standing when you take the picture. The ExpoDisc acts as a light meter reading the Incident light. Now snap a shot. The photo you just took will show up as a solid shade of gray, possibly with tones of blue or orange. Just depends on your lighting conditions. Below is the color my camera captured when I took a reading before shooting the flowers.
4. Find your Custom White Balance in your camera’s menu. (In a Canon 5D, press the Menu button, then use your Quick Control dial to scroll down to Custom WB) Press your Set Button. Select the image you just shot by pressing your Set Button again. The Canon 5D menu looks like this:
5. Done. Now all the shots you take while your White Balance is in the Custom mode, will use the photo you took with your ExpoDisc as the reading for precise White Balance.
If your lighting changes, you must take another photo with your ExpoDisc and reset the Custom White Balance. For instance, if you are shooting outdoors, and a cloud comes over, your lighting just changed, and you must go through the 5 steps above to get a new reading.
If you are considering buying an ExpoDisc, there are two types. One is neutral, the other is for portraits. I recommend the neutral because it measures pure light without adding any tones. The portrait ExpoDisc adds a warm tone. I shoot a variety of subjects, and do not want the tone contained in the portrait version. Buy the size as you would a filter that fits on your lens. It comes in 52, 58, 62, 67, 72, 77, and 82 mm threads. If you have several lenses, and don’t want to buy one for each size, get the size that fits your largest lens. You can hold the ExpoDisc up to your smaller lenses, and it works just fine.