The Color Temperature Scale
Introduction To White Balance (WB)
Color brings out details in photographs. It’s not just the image, but also the colors that elicit an emotional response. They can show joy with vibrant colors, while dark and muted colors could convey a different type of mood. The details are associated with the colors and referred to as temperature. While temperature in physics and chemistry is associated with the measure of hot and cold, in imaging it is more about the wide range of color from RED to BLUE.
Color temperature is measured in Kelvin or better represented by the letter K. It is dependent on the light source on a radiated black body object. This refers to the radiation of natural light, which shifts in colors based on their wavelength on the electromagnetic spectrum. Light sources also shift, which represents the colors that we see. Just like in measuring hot and cold, color temperature has a warm and cold range. Cooler colors are toward the BLUE end of the color temperature scale, while warmer colors shift toward YELLOW and RED.
The color temperature scale shifts from warm to cool. The warmer color temperature is between 1,000 and 5,000K. The cooler color temperature range is between 6,000 and 10,000K. The cooler the light, the higher the temperature. The warmer the light, the lower the temperature. This is totally opposite from hot and cold temperatures. On a DSLR camera this can be adjusted to a custom setting in White Balance (WB).
WB is often used by photographers to get the most accurate color for the images they are capturing. Seasoned photographers will sometimes use a custom setting or a color checker card to get the most accurate color representation for their images. Many will choose Auto WB which allows the camera to set the color balance for their images. There are other WB settings (refer to your camera documentation), but the idea is to adjust for color accuracy in images.
Here is a list of common lighting conditions with the color temperature.
- Candlelight: 1900K
- Incandescent Light: 2700K
- Sunrise/Golden Hour: 2800 to 3000K
- Halogen Lamps: 3000K
- Moonlight: 4100K
- White LEDs: 4500K
- Mid-day: 5000 to 5500K
- Camera Flash: 5500K
- Overcast/Cloudy: 6500 to 7500K
- Shade: 8000K
- Heavy Cloud Cover: 9000 to 10000K
- Blue Sky: 10000K
Most DSLR cameras have preset WB that can be changed. These WB setting presets will try to get the most accurate color, but depending on the lighting conditions. It could still not accurately create the colors, but the closest it can get is what the photographer needs for their images. Further color correcting can be done in post.
An example of using color temperature in WB is to try to get the correct color representation in an image. When a photographer wants to capture a fine summer’s day, they can set their WB to daylight. It brings out a more natural look that can be further enhanced or retouched later.
For a much cooler look that can represent early evening on an overcast day, set the WB to Cloudy. This captures a more relaxed, but dull mood which appears more muted rather than vibrant.
This is an example of a shot taken during the “Golden Hour”. This is the time of day before sunset when the sun is closer to the horizon. It creates a reddish and softer color on the image.
Sometimes retouchers want to correct the colors by adjusting the color balance in post. This is accomplished by using an image editing software. The reason this is done is because there could be color mismatches on an image taken when the Auto WB setting was used. There are times the photographer will set the camera to Auto WB and do color correcting later. Color casts can also occur when the light sources vary on an image creating a certain color tint. This is an unwanted part of the image and retouchers will work to remove this.
Color temperature shows an image from the light source. WB is used to get a more approximate color accuracy in images. They can also be used in image editing software for color correcting. The temperature is measured in units called Kelvin (K). Cooler colors have a higher temperature, while warmer colors have a lower temperature. It is best to shoot images stored in the RAW image format because they store the most details allowing WB to be adjusted in post.
