In general, the subject matter can be embodied in methods, systems, and program products for using a display of a computing device as a light source. The computing device receives a first image that was captured by a camera of the computing device, determines a brightness of at least part of the first image, selects an intensity of a light source that is to be presented by the display of the computing device, the intensity of the light source being selected based on the determined brightness of the at least part of the image, presents the light source by the display of the computing device, the presented light source having the selected intensity, and receives a second image that is captured by the camera of the computing device while the computing device is presenting the light source on the display using the selected intensity.