An automated beam profile analyzer has been developed to evaluate light beam profiles of both coherent and non- coherent light sources and to determine their suitability for use in photodynamic therapy (PDT) or photodiagnosis (PD), where both controlled and effective light delivery is crucial. It is the purpose of the system to characterize the output properties of the light source in terms of the stability, irradiance, and beam uniformity. The output light analysis system described is capable of quantitative analysis on a large variety of lamp sources for potential use in different photobiological applications, such as photosynthesis, environmental photobiology, and photomedicine, as well as many industrial applications. This system is described in detail in reference 1. Figure 1 is a pictorial description of the automated beam profile analyzer.