Understanding Neutron Radiography Reading V-Kodak Part 2 of 3

When x-rays, gamma rays, or light strike the grains of the sensitive silver
compound in the emulsion, a change takes place in the physical structure of
the grains. This change is of such a nature that it cannot be detected by
ordinary physical methods. However, when the exposed film is treated with a
chemical solution (called a developer), a reaction takes place, causing the
formation of black, metallic silver. It is this silver, suspended in the gelatin on
both sides of the base, that constitutes the image. (See Figure 69) The details
of this process are discussed in greater length later. Although an image may
be formed by light and other forms of radiation, as well as by gamma rays or
x-rays, the properties of the latter two are of a distinct character, and, for this
reason, the sensitive emulsion must be different from those used in other
types of photography.
Charlie Chong/ Fion Zhang
Radiography in Modern Industry. Rochester, NY: Eastman Kodak Co. 1980