Single-pixel cameras produce high-resolution images using a single pixel to detect light. They do not need lenses and the entire picture is always in focus. Physicists have used them to make movies and create 3-D images. Now scientists at Jiaotong University in China have built a single pixel camera that can see around corners, photographing objects even when they are not in direct view. The device images around corners with single-pixel detection and repeats the process 50,000 times. Read on.