The invention of photography was only possible due to the camera obscura effect which produces an upside down image of a scene on the back wall of a box when light is reflected through a tiny hole in the box. The camera obscura effect has been known since classical times. The invention of photography required that the image be fixed and reproducible and this was not achieved until the 19th century, after the discovery of the light sensitive properties of certain silver compounds, which resulted from scientific discoveries in the preceding three centuries. After photography was invented it was improved by the invention of color photography and became cheaper and easier. The order of discovery was inevitable and is an example of how social and cultural history has to follow a particular course determined by the structure of the world around us. Photography is only possible due to the existence in nature, of the camera obscura effect and of the existence of light sensitive compounds and only when they were put together, was photography invented.