Isocandela Curve (G.B.)
Isocandela Line (U.S.A.)
A curve traced on an imaginary sphere with the source at its centre and joining all the points corresponding to those directions in which the luminous intensity is the same, or a plane projection of this curve.
Note: This type of diagram is sometimes used instead of the curve of luminous intensity distribution.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)