ABSTRACT

The extremes are the lightest and the darkest groups of grays or colors in a photograph. For years they were the parts of the picture most likely to lack quality because of the inherent, irremediable defects in film. Good photographers managed to get excellent pictures anyway because they paid a lot of attention to these defects and how to minimize them. The characteristic curve is a way to compare two grayscales: one representing exposure steps in the scene and the other representing brightness values in the recorded image. Photographers and scientists who invented the scale deliberately decided to divide the range of possible grays into equal steps. Photographers almost never use a diagram of a characteristic curve in their daily work, but they keep a mental image of the shape of a curve with them always because it helps them previsualize how a real scene will appear in the picture.