Picture of the Day

Focusing Diffracted Sunlight

November 29, 2021 ―- Archive

Macro and Micro Picture of the Day 2021-11-29
License: Creative Commons Attribution 4.0 International License.

This picture shows a DVD focusing sunlight via diffraction. The DVD is acting as a circular diffraction grating. Since different colors (wavelengths) are diffracted at different angles, they will be focused at different distances from the DVD. At this particular distance, blue light is being focused. The black disk in the center blocks light coming through the center of the disk so that the focus point can be better seen.

Equipment used: Canon EOS Rebel T5i with a standard zoom lens (EF-S 18-55 mm).

Authors: Richard Hollos and Stefan Hollos