The Radiographic Image
Course Number: 571
Image Magnification
Image magnification describes the proportional enlargement of a radiographed object in comparison to its actual size and is influenced by the following factors:
An increase in object-to-film distance leads to greater magnification of the radiographic image, whereas a reduction in this distance decreases magnification. (Figure 8)2,4,7,8
Figure 8.
Comparison of magnification when the object to film distance changes. A short distance (A) shows less magnification than a long distance (B).
Increasing source-to-object distance only will decrease the magnification of the radiographic image. Decreasing source to object distance only will increase the magnification of the radiographic image (Figure 9).2,4,7,8
Figure 9.
Comparison of magnification when the source to object distance changes. A short distance (A) shows more magnification than a long-distance (B).