Lamp of variable spectrum for photographic uses

Photography is a unique rapidly growing interdisciplinary field encompassing aspects of science, art and technology. Expectations of photographers are steadily increasing with the development of technology. One of the areas playing a crucial role in photography is lighting. Consequently, several types of light sources for photographic use have been developed. The ongoing research in this field concentrates on lamps with tunable CCT (Correlated Color Temperature).
In this paper, we present a lamp, whose emission spectrum can be tailored without affecting the output luminous flux. Intended for photographic uses, the lamp is based on an integrating sphere and a selection of LEDs. As the LED drivers, DC-DC converters controlled by a Raspbery PI were applied. Design process, including the selection of LED wavelengths, is presented. Output characteristics of the lamp were measured using a setup containing a spectrometer. The results of these experiments show good agreement with the spectrum set on the microkomputer.