This research examines the lighting systems in four European museums (Brandhorst Museum- Munich, Kiasma Museum of Contemporary Arts- Helsinki, Acropolis Museum- Athens and Guggenheim Museum- Bilbao), and also the concept, the building program and the objectives that the architects wished to achieve. One can notice  that the aim of every architect in all four museums, that are located in very different places in Europe, is the best possible exploitation of natural lighting (for this reason specialized systems that filter the natural light and bring it in the parts of the museum where its presence is necessary are used), and its combination with artificial lighting where it is necessary for the better performance of the exhibits.

There is also a general reference to the museum lighting and specifically to the promotion and protection of the exhibits as well as to the design techniques for the better and more accurate performance. Potential problems that can cause damage to the exhibits or adversely affect their observers (like glaring problems, destruction of the exhibits from exposure to radiation) are also indicated.

In the second part  which is directly related to the first and specifies it, there is the technical report of CIE (International Commission of Illumination) which consists of three parts. The first part contains the main causes of destruction of the exhibits and basic terms such us spectral power distribution of the radiation and the spectrum of the materials which receives the radiation, in the second part there are some recent researches while in the third there are recommendations for lighting. It should be noted that the standard of CIE is not mandatory but advisory.