This lab activity, presented by John Chamberlain, is one of four on the topic of interference and diffraction. In this 6-minute video, Chamberlain demonstrates the measurement of diffraction of white light through a diffraction grating and how to calculate the wavelengths of light produced through the grating. This lab, 1-5B, is one in a series of 20 available on the Fundamentals of Light and Lasers. These videos were created as a supplement to the Fundamentals of Light and Lasers curriculum available through OP-TEC, but can be used independently to guide lab activities related to this topic. Contact OPTEC for more information on their available educational resources