What characterizes high key lighting in a photograph?

High key lighting is characterized by a bright scene that is predominately filled with light. This style of lighting minimizes the presence of shadows and uses a variety of light sources to create an evenly lit environment. In high key photography, the overall tonality tends to be on the lighter end of the spectrum, producing a cheerful, airy feel that is often used in fashion, product, and portrait photography.

This approach contrasts with techniques that utilize more dramatic lighting setups, which generate distinct shadows and emphasize areas of contrast between light and dark. Such techniques are not aligned with the essence of high key lighting, which seeks to create a harmonious, vibrant atmosphere. The absence of pronounced shadows and the overall brightness are what distinctively define high key setups, making the correct choice clear.