Incandescent lamps provide a point source for light. One of the
distinguishing features of a point source is that is can be controlled and directed very
easily. In this diagram, a point has been placed inside a reflectorized fixture
resulting in a spot of light at the work plane. The size and intensity of this
spot can be adjusted by changing the shape of the reflector.
Many incandescent lamps already have this reflector feature built in. They include the "R", "PAR", "MR", and "ER" lamps.
Point sources also create contrast in an image by casting shadows in "deeper"
areas of the object. As shown here, the object on the left is illuminated by a line source. You can see very little contrast in this
object. The object on the right is illuminated by a point source which creates much more contrast. In
applications where contrast is important, incandescent or some other point source of
light make a good choice.
Incandescent lamps also provide excellent color rendition. Their color rendering Index approaches 100 or approximately the same as sunlight. Good color rendering properties make this source an excellent choice for retail applications, especially those which need to highlight different colors.
Incandescent lamps also operate at very warm color temperatures. Warm temperatures tend to set a soothing mood to the environment. This type of mood or ambiance is important in areas such as lobbies and restaurants where the primary activity is relaxed. High productivity areas need cooler sources of light and do not lend themselves to incandescent lighting.
