How is a Radiographic Image Formed?

When an x-ray passes through an absorber, it gets differentially absorbed by what constitutes the absorber and the thickness of each component. When the x-ray beam exits this absorber, it will have varying levels of intensities. This variation will be recorded on a radiographic receptor as different densities generating the radiographic contrast. The densities related to a thick absorber (i.e., aluminum) will be brighter than the densities of the thin absorbers (Figure 1).1-5

Figure 1. Illustration of a radiographic image formation.
Illustration of a radiographic image formation