Photograph of the Sun with sunspots, dated 20 July 1875 (?), taken by the French astronomer Pierre Jules Cesar Janssen (1824-1907) at the Meudon Observatory, Paris. This early photograph of the Sun was taken using a wet collodion plate with its poorly light sensitive film emulsion. Despite the brightness of the Sun it needed an exposure of 23 seconds through the telescope to record a useable image.
© Science Museum / Science & Society Picture Library