High-key lighting

Please note that the content of this book primarily consists of articles
available from Wikipedia or other free sources online. High-key lighting
is a style of lighting for film, television, or photography that aims to
reduce the lighting ratio present in the scene. This was originally done
partly for technological reasons, since early film and television did
not deal well with high contrast ratios, but now is used to suggest an
upbeat mood. It is often used in sitcoms and comedies. High-key lighting
is usually quite homogeneous and free from dark shadows. The terminology
comes from the key light (main light).