In any photography club, magazine, book or even when a few photographers are just talking, you will hear references to high and low key black and white pictures. These buzz words are bandied about by even those who do not really know what they mean. For most people the words high and low in this context mean the degree of brightness (or harshness) of the lighting used. Yes, lighting does play a role but high and low key photographs and much more than the lighting effect.
A photograph is, in the final analysis, just a 3 dimensional reality converted into a 2 dimensional image. But the image conveys not just an impression of the reality, but also the way a photographer sees it. A color picture of a neglected garden may show a few bright flowers in contrast to the dead vegetation around it and give an impression of what was. A black and white picture of the same scene may create a stark impression of desolation and abandonment, with an impression of a few flowers surviving amidst a decay that will soon overtake them also. Whether the black and white photos focuses on the surviving flowers or the desolation depends on whether the picture is high or low key.
Contrast play a very important role in black and white photography and a high contrast will can make the few remaining flowers stand out while a low contrast can make then merge into scene. But in creating the mood, it is the key that counts.
A high key photograph will have predominantly light tones, a sharp focus and be brighter. The tones will range from a medium gray to white with very few, if any, black or very dark areas in the picture. The high contrast of a high key black and white photo presents the image without highlights or placing any emphasis on specific areas of the picture – to refer to the example of the decaying garden, the surviving flowers are part of the image and not a statement about their impending death. The high key picture presents a “fact” without any attempt to interpret it. A high key photograph uses front lighting focused over the entire scene to reduce the amount of shadow in the composition. Because of the “light” effect of a high key picture, it can be used to avoid drawing attention to features that are unimportant. A face photographed in high key will not draw attention to any small pimples that may be on the cheek.
A low key photograph will have tones that range from a light grey to black with a high degree of contrast to emphasize a certain aspect of the picture. Using the same example, it will highlight the few flowers that have survived and not the decayed garden itself. The state of the garden becomes only an environment and the picture is of the flowers. The “fact” of the decay is secondary. Low key pictures are shot with oblique lighting to increase the amount of shadow and lay emphasis on the brighter areas. A low key photo of a table full or ornaments will have the key ornaments in the lightest tones, the rest will be darker and the background black. The focus is on the ornaments, not the table or the room.
If the difference between high and low key, black and white photos has to be summarized in a few sentences it would be: High key pictures are bright, cheerful and factual. Low key ones are darker, somber and convey more mood than fact.