Quality of Light
Light from a point light source such as an open flash or the sun is described as having a ‘hard quality’. The directional shadows created by this type of light are dark with well-defined edges. The shadows created by the sun are dark but not totally devoid of illumination. This illumination is provided by reflected skylight. The earth’s atmosphere scatters some of the shorter blue wavelengths of light and provides an umbrella of low-level light. Artificial point light sources create a much harsher light when used at night or away from the softening effects of skylight. The light from a point light source can also be diffused, spread or reflected off larger surface areas. Directional light maintains its ‘hard quality’ when reflected off a mirror surface but is scattered in different directions when reflected off a matte surface. This lowers the harshness of the light and the shadows now receive proportionally more light when compared to the highlights. The light is said to have a softer quality. The shadows are less dark (detail can be seen in them) and the edges are no longer clearly defined.
The smaller the light source, the harder the light appears.
The larger the light source, the softer the light appears.
The control over quality of light is an essential skill when on location. Often the photographer will encounter scenes where the quality of the available light creates enormous difficulties for the latitude of the image sensor. The photographer must learn techniques to alter the quality of light or risk loss of detail and information. The quality of light, whether hard or soft, can be changed by diffusion and reflection.