Image courtesy ShutterFliesPhotography
In our last article "Back To Basics: Light: What it is, Measuring it and Exposure Control" we briefly mentioned that one of the parts that light consists of is Wavelengths - which is, at the end of the day, what gives light its color.
It is important to understand color when shooting photography. This is the skill that will help you out BIG TIME when it comes to making sure your pictures do not come out with unnecessary color casts, tints and shades - like a blue bride - or an orange groom - or a yellow child!
The Color of Light Follow me - the wavelength is the range of the light. Meaning, the extent (length) to which the light will be a certain shade until in changes color. These wavelengths are measured in nanometers (nm), a measurement of length (a billionth of a meter to be exact). These range from (400 nm) Violet, Blue, Green, Yellow, Orange, Red (700 nm). These wavelengths are the "visible" spectrum's that the human eye can see. Each wavelength has a color and this color is measured in Color Temperature using the unit Kelvin.
Higher color temperatures of around 5,000 K are cooler in color (blueish) and the lower temperatures around 2,700–3,000 K are warmer and tend toward yellow and reddish.
Color Temperature states that the subject that you are shooting, will encompass the hue or color shade that the light source you are using has. For example; you'll learn that shooting under Tungsten lighting will give you a color cast of red. Shooting under fluorescent lighting will give you a green cast etc etc. So if you're shooting a model under a street light, you know (from experience) that the model will come out a shade of green because the street light is fluorescent. We'll talk about how to fix this next (if you want to fix it that is).
Balancing Color (Balancing the White or White Balance) Because white light, which is around 5500 K, (probably what you're looking for to get the most correct colors of your subject, especially if photographing models, weddings or people), is a mixture of all the wavelengths together, you can measure the color of the light source you're using. For example, a light bulb, which is around 2500 K. Subtract that from white light (5500 K), which equals 3000 K. Add 3000 K to your image and you'll have a color balanced image.
Well, this is all too complicated when you're busy shooting and thinking about 100 different things... so there are easier ways.
Some rely on their white balance feature on their cameras, some use a Gray card using their Custom White Balance setting - the latter being the most accurate.
Camera White Balance Settings
Different settings will compensate for different colors:
- Auto White Balance will decide for you what the color cast is and automatically compensate it.
- Kelvin setting will compensate for you using the kelvin amount you manually enter into the camera when using this setting. It will take your entry and subtract it from around 5500 K (white light). This is a setting used by those who are more versed in color temperature but I challenge everyone to try it and see how it works.
- Tungsten will compensate for red using a shade of blue.
- Fluorescent will use a magenta color to compensate for the green.
- Daylight will let the camera know that no compensation is necessary based of the fact that daylight is around 5500K.
- Flash is the same scenario as daylight since flash is white light.
- Cloudy and shade will use a red color to compensate for the blue color temperature that clouds and shade cast on a scene.
- The Custom white balance setting is probably the most accurate. With this setting you need to find or add a neutral color to your scene. You can add an 18% gray card to your scene. Set your camera to Custom white balance and take the reading from the gray card and save the image as your color balance reference. As shown in the Zone System the gray card has 18% reflectance across the visible spectrum and is therefore neutral.
It's important to remember that there are no rules in photography, just guidelines and if you understand the guidelines you can manipulate them to your hearts content.