Light, be it natural or artificial, is the key component of photography. No light means no photograph. But to grasp light more fully, you need to understand that it has a color temperature, which puts different color casts on images. DSLRs come with white-balance settings, which make it easier to correct for these casts. But you still need to know how these work, and how to control your white-balance settings to get the best results.
Different times of day and different artificial lighting conditions create different color temperatures. These temperatures are measured in a unit known as kelvins (K), with neutral light being produced at 5000K. Let’s have a look at some of the different temperatures produced by different sorts of light.
· 1000-2000K: Candlelight
· 2500-3500K: Tungsten Light (Normal household bulb)
· 3000-4000K: Sunrise / Sunset (Clear skies)
· 4000-5000K: Fluorescent Light
· 5000-5500K: Electronic Flash
· 5000-6500K: Daylight (Clear skies with sun overhead)
· 6500-8000K: Overcast Skies (Moderate)
· 9000-10000K: Blue Sky
As the list shows, flash is balanced to be as close to natural light as possible to give realistic results.
White Balance Modes
Back when film cameras ruled the world, working with different types of light could be complicated, and often required the use of different types of film or filters. Life is a lot simpler now — even the most basic digital cameras come with a white-balance button to allow for alterations according to different lighting conditions.
Here are a few common white-balance settings you’ll find on cameras, and what they mean:
AWB (Auto White Balance)
The default setting for white balance is pretty reliable on modern digital cameras, and will set the color temperature fairly accurately. It’s important to note that some complex lighting systems may be beyond it, though, which is why you need to understand the other settings.
No prizes for guessing that this setting is designed for shooting in daylight! But do be aware that it’s only designed for use when there are clear skies and sun overhead.
Use this setting for when the skies aren’t clear, as the camera will warm up shots slightly more than in daylight mode.
For use in shady situations, this mode will compensate for the slightly blue-green tinge on subjects by adding in a touch of yellow.
For use with external flashguns (also known as speedlights), this mode warms up shots a little to compensate for the cool tones of flash.
Tungsten light (found in normal household bulbs) casts a particularly unattractive orange color over photos, which this mode adjusts for. Artificial light can be one of the hardest for digital cameras to cope with and presents a situation where you may need to set the white balance manually.
Fluorescent lighting is found in strip lighting and can have green or blue tinges, which this mode will remove. On some DSLRs, you’ll find several fluorescent settings to deal with different casts.
This mode allows users to set the color temperature at will, so you can tweak the kelvins in small amounts for a more precise reading.
Studio photographers usually use this mode when it’s vital to have a pure white background. It works by using a grey card to set the white balance. A grey card is a piece of card set to 18% grey, which is exactly halfway between pure white and pure black. This gives the camera a midpoint to work from. You take a shot of the grey card and then, in custom mode, select this shot for the camera to take its white balance from.
A few more things to consider
AWB can be pretty effective, particularly if you’re working with a strong, neutral light source, such as a powerful flashgun, or bright sunlight, because the light will cancel out any color casts. But some subjects can be a bigger problem for AWB — in particular photos that have an abundance of warmth or coolness. The AWB can misinterpret these tones as creating a color cast over an image, and will then try to correct this. For example, in an image with a lot of warmth, the camera will cast a bluish tinge over the image in an attempt to balance it out.
It’s also a good idea to manually set the white balance when there’s a combination of ambient and artificial lighting. This avoids confusing the camera and allows you to choose the look you want.
Do you have any other white-balance tips to share? Tell us in the comments below!
Top image: Magic winter landscape by elen_studio