In the framework of imaging, lighting systems have always played a key role due to the primary importance of both the
uniformity of the illumination and the richness of the emitted spectra. Multispectral imaging, i.e. imaging systems
working inside and outside the visible wavelength range, are even more demanding and require to pay further attention
to a number of parameters characterizing the lighting system.
A critical issue for lighting systems, even in the visible light, is the shape of the emitted spectra and (only in the visible
range) the Color Rendering Index.
The color we perceive from a surface is our eyes' interpretation of the linear spectral combination of the illuminant
spectrum and the surface spectral reflectance. If there is a lack of energy in a portion of the visible spectrum, that portion
will turn into black to our eyes (and to whatever instrument) regardless the actual reflectance of the surface. In other
words a lack in the exciting energy hides part of the spectral reflectance of the observed subject.
Furthermore, the wider is the investigated spectrum, the fewer are the sources of light able to cover such a range.
In this paper we show how we solved both the problems of the not uniformity of the light beam, independently on the
incident angle, and of the selection of a light source with energy rich and continuous enough emitted spectrum.