Worlds of David Darling
Encyclopedia of Science
Home > Encyclopedia of Science

Rayleigh criterion

A rule for how finely a set of optics may be able to distinguish the location of objects that are near each other; it was proposed by the English physicist Lord Rayleigh. The criterion for resolution is that the central ring in the diffraction pattern of one image should fall on the first dark interval between the Airy disk of the other and its first diffraction ring; for an objective lens of diameter d employing light with a wavelength λ (usually taken to be 5600 Å), the resolution is given approximately by 1.22 × λ/d.

Related entry

   • Dawes limit

Related category