Choosing the right clinical camera. Part I.

Our recommendation is a 90-105 mm macro lens focusing from 1:1 to infinity and a minimum aperture of f/32. A reputable brand should be preferred: Nikon, Canon, Minolta, Sigma etc.... A 105 mm macro lens allows for adequate working distance (approx. 130 mm for a straight view at 1:1 magnification). A 105 mm macro lens induces insignificant perspective distortion and has a large range of aperture. Lastly, it provides for a magnification scale ranging from 1:1 to infinity and is optically excellent. The working distance of current camera systems extends approximately from 4 4/8" or 114 mm, to 7" or 180 mm, at 1:1 magnification. Again these differences are mainly due to lens design and mounted components, (filters, bracket, lighting systems). A minimum of 5" or 125 mm of working distance is desirable for physical access of your camera and proper illumination of the photographed object. However, adequate lighting also depends upon the type and location of your lighting system especially for higher magnification photographs. Part II will examine the different lighting systems on the market and try to decide which is most adapted to your needs. It will answer your questions about the use of the operatory light while focusing, the red eye problem and the use of polarizing filters to decrease the amount of reflection from the flash.