A photo finish occurs in a sporting race, when two (or more) competitors cross the finishing line at near the same time. As the nake eye may not be able to discriminate between which of the competitors crossed the line first, a strip photo, a series of rapidly triggered photographs, or a video taken at the finish line may be used for a more accurate check. Nowadays, the photographs may be digital but usually involve special equipment. They may be triggered by a laser or photovoltaic means.