For the first time, an international team of researchers has visualized the light-sensitive protein archaerhodopsin-3 (AR3) at unprecedented resolution using the I24 and B23 beamlines at Diamond Light Source. The photoreceptor is expressed by Halorubrum sodomense, an organism that grows in the Dead Sea, but is best known for its applications in optogenetics experiments, in which it is used to silence individual neurons and to detect changes in cell membrane voltage. These new structures open the way for the development of new tools and methodologies in the fields of neuroscience, cell biology and beyond.