Moreover Wood lamps are not pure UV sources. They have a residual visible emission that superimposes on the fluorescence emission, and compromises the correct acquisition and reproduction of the fluorescence image.

Furthermore, considering the fluorescence emission intensity, with this system it is only possible to acquire fluorescence images in dark rooms, since day light is generally much more intense than fluorescence emission.

For this reason, till now the fluorescence images acquisition was a diagnostic method that could be employed only for works of art that could be moved in a dark room, while in many cases this transportation can be dangerous and sometimes impossible (as i.e. in the case of very large paintings or frescos).