Look at this picture. Does it seem natural for the time when it was taken (1915)? I'm sure most of you will say that it was photoshopped and fake. Well no, it's a real photo taken by the Russian photographer Sergey Prokudin-Gorsky.
His process used a camera that took a series of three monochrome pictures in sequence, each through a different coloured filter. By projecting all three monochrome pictures using correctly coloured light, it was possible to reconstruct the original colour scene.