Simple camera calibration for light measurements

The availability and decreasing prices of digital photographic cameras using megapixel sensors could point to its use as high quality light measuring devices if simple and effective calibration procedures could be put to work. This paper proposes such a system, using a common digital camera combined with low cost reference color charts. The procedure to obtain the response function of the camera, the production of the color chart and its calibration is presented. In this way, it is possible to obtain light measurements otherwise only possible with sophisticated and expensive equipments.