A simple method for measuring the period of e-beam written gratings is described. The technique allows for measurement of grating periods using a light microscope. Grating periods can be determined with a resolution of about 0.1 Angstrom. Twenty near field holographic photoplates have been made using this method with excellent results. The technique is described for use on a JBX 6000FS electron beam lithography system with fine pitch control software, but may be applicable to other systems.