This Data Book has been divided into two distinct sections, one on Ultraviolet Photography and the other on Fluorescence Photography. The purpose of this division is to emphasize the fact that two types of photography are involved. It has often been considered that ultraviolet photography is also fluorescence photography. Although it is common technique to use ultraviolet radiation to produce fluorescence, this is not the only radiation which can be used for the purpose. Also, since it is possible to photograph an object completely by ultraviolet with no fluorescence produced, the reason for the division is further justified. If an object is photographed by ultraviolet reflected from it or transmitted through it (as in microscopy), the technique should be called ultraviolet photography. In the latter case, however, involving a microscope, the technique is sometimes referred to as ultraviolet micrography. If certain radiations (including ultraviolet) are used to excite fluorescence in an object, the recording of the resultant fluorescence is called fluorescence photography. -- CAL