The ratio of image size to object size is known as what?

The ratio of image size to object size is referred to as magnification. This term is fundamental in radiography because it describes how much larger or smaller the image appears compared to the actual size of the object being imaged. Magnification occurs due to the geometry of the imaging process, including the distance between the source of radiation and the object, as well as the distance between the object and the image receptor. Understanding magnification is crucial for interpreting radiographs accurately and ensures that measurements taken from images reflect true object dimensions.

While distortion refers to the alteration of the image shape or proportions, penumbra describes the blurred edges of an image that can affect clarity, and mottle relates to graininess or noise in the imaging, none of these concepts provide a relationship between image size and object size as clearly as magnification does.