Resolution and optical sectioning in the confocal microscope


T. Wilson, Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, U.K. Tel: +(0)1865 27 3116; Fax: +(0)1865 27 3905; e-mail:


In this short review, we present a self-contained discussion of the image formation properties of the fluorescent confocal microscope. The optical sectioning or depth discrimination property is discussed in detail and new analytic formulae are presented, which relate the optical sectioning strength to the wavelength, numerical aperture and pinhole aperture size in a particularly simple fashion.