High key and low key photography are closely related to contrast as they both make an intensive use of it in images. However, it’s used by each type in quite a different way.
When taking a photo of a dramatic portrait for instance, you can choose to make it a high key or low key image or just a “regular one.” The choice will create the mood that you want the photo to convey to viewers.
High Key photography and low key photography are typically considered to be happy and bright shots and low key images portray quite a bit of atmosphere and tension and are dramatic in nature respectively.
A high key photo is bright and you can make it that way by setting the camera’s exposure levels at high values. But be careful not to over expose them.
A high key shot also lacks contrast as the tone is more or less bright right across the photo. This is done by setting the photo’s lighting carefully. The photo will also lack shadows as the shadows cast by subject are actually suppressed by the lighting in the scene.
With a low key image, you’ll notice that there is a darker tone and the predominant color is typically black. There will also be a lot of dark areas in the image. Many low key photos focus on contour lines and emphasize them with highlights.
These is the major difference between low key and high key photography.
Low key shots also have a lot of contrast in them. They often make use of a rim light, which surrounds the subject and illuminates just the shape’s contour. This creates a contrast between a bright contour and dark shape.
A technical definition of high key photography would be using lighting to create tones that are mainly between grey and white, with no or only a few black or dark grey tones. Try to imagine a photo of a woman in a white gown standing in front of a white background.
High key photography is often used in portraits, especially with children and women as the soft, white tones create an aura of innocence in the images. The method also works well in black and white.
However, many people like to simulate high key photography in digital editing programs as they feel it gives them more control over the photo’s final outcome.
When printing a high key photo, you need to make sure the ratio of the tones is correct. Therefore, if you print the photo too dark you’ll lose the high key effect and if it’s printed too light, you won’t be able to see much detail.
To play with high key and low key photography for the right kind of photos is the key.