A line-scan camera has a single row of pixel sensors, instead of a matrix of them. The frames are continuously fed to a computer that joins them to each other and makes an image. This makes possible sharp pictures of objects that have passed the camera at high speed. Sporting races commonly use this kind of camera to make photo finishes, i.e. determine the winner when multiple competitors cross the finishing line at nearly the same time. These cameras can also be used as industrial instruments for analyzing fast processes.