For optical design and product qualification, the output color and luminance distributions of large light sources are needed to qualify and predict the performance of architectural, automotive, street, security, entertainment and other lighting systems.
However, these distributions are difficult to measure because of both the size of the source and the large space required for the measurement. For these lighting systems, measuring in the far field often requires a substantial distance – three meters or more is common – so that setting up the measurements in a controlled laboratory environment can be difficult and expensive. We describe an alternative method to measure large light sources that is applicable to general lighting systems, deployed in a compact laboratory space, and provides full near-field data.
