Calibrating lenses for standard scales of reproduction with digital SLR cameras.

This paper is an update of previous work undertaken by one of the authors (SY) that outlined a method for establishing standard scales of reproduction with digital SLR cameras for clinical photography. Recent experience in the authors' department has raised some issues with using the published formulae for calculating subject and working distances to achieve accurate magnifications. The authors explain a more pragmatic approach to calibrating lenses used on a range of Nikon digital SLR cameras.