English, 12 pages, 3 figures, 14 references

Many luminance measuring tasks require a measurement of the luminance distribution of the whole
viewing field. The approach of using an imaging device like a digital still camera represents a simple
approach to such measuring tasks.
Luminance measurement cameras, that are specially designed for measuring tasks with high accuracy,
already exist. Due to the high level of performance required from these cameras they are very
expensive and for many tasks they are simply not affordable. Therefore it would be desirable to be
able to measure luminance with an ordinary digital still camera that is available at a reasonable price.
This paper presents a method for the use of digital still cameras as luminance meters. A calibration
of the camera is performed with the help of an OECF (opto-electronic conversion function) measurement
and the luminance is calculated from the camera’s digital RGB output values. The test method
and computation of the luminance value, irrespective of exposure variations, is described. The error
sources that influence the result of the luminance measurement are discussed.