Talbot sensitized paper to light with a silver salt solution. He then exposed the paper to light. The background became black, and the subject was rendered in gradations of grey. This was a negative image, and from the paper negative, photographers could duplicate the image as many times as they wanted.
The Calotype Process
The oldest photographic negative in existence
The inventor of the first negative from which multiple postive prints were made was Henry Fox Talbot.
Window in the South Gallery of Lacock Abbey made from the oldest photographic negative in existence
Henry Fox Talbot 1835
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