Abstract
Clinical photographers and their clinical colleagues frequently place linear scales within the area being photographed to give an indication of the size of a lesion or area of interest. On occasions these scales are intended to be used for quantitative measurements. It is known that the placement of linear scales in respect to the area of interest can have a marked effect on the perceived or measured size. The author has reviewed a number of articles that have reported attempts to quantify the effects of scale placement and the relationship of subject and image planes (perspective) and summarizes their findings.