Methods of Representing Light Distribution

In section IV–1 it was stated that, if the distribution of the luminous intensity of a light source is known, it can be reproduced either numerically or graphically. The numerical method is very simple, entailing only a table specifying the different directions and associated intensities; this is obviously a very convenient method when the data are required for computations, as it is then unnecessary to read the required values from graphs. If a table compiled from measurements of the light distribution is available, the curve is therefore superfluous, but, should it be necessary to interpolate from the values given, a curve will be necessary. On the other hand, a table is seldom used to characterise a light source as it does not present a clear picture of the light distribution.