William and John Herschel

William and John Herschel, father and son astronomers, contributed to imaging science through advancements in telescope design, the development of thermal imaging, and contributions to the field of photochemistry.

William was a prolific telescope designer, having constructed over 400 instruments during his lifetime. One of these, having a 40 foot focal length, was the largest in the world at that time. William is also credited with the discovery of infrared radiation beyond the red end of the visible spectrum.

His son, John, was the first to create an image using infrared radiation by placing a blackened piece of filter paper soaked in alcohol in dispersed sunlight. He is also discovered a way to “fix” images created with silver halides, thus preventing them from quickly fading away.