holy mouse-traps, Batman!

Mouse-traps (cameras wth a thumb sized hole in front to check exposure status) c1838.

Toronto. Sitting comfortably on vacation on the shores of Lake Como, Henry painted the lush Italian landscape. 1834 was a wonderful year. As he idly dreamed, he thought about ways to capture the scene without recourse to his brushes.

Back home in England, William Henry Fox Talbot, to use his full name, began to experiment and came up with salted papers based on the earlier work of his fellow countryman, Wedgwood.  The paper was placed at one end in a small wooden box. A lens was attached to the other end and focussed to sharply record a black and white image. A hole and cork in the front of the box next to the lens let Talbot see when the salt-paper was sufficiently exposed.

He discovered a subsequent wash in a weak salt bath would removed the paper’s sensitivity to light. Only one problem remained – the image on the paper was reversed! In a stroke of genius, he placed the reversed image over another sensitized paper in bright sunlight and voilà! He made a positive image. Not only that, but he could replicate the positive image at any time and in any quantity.

A few other issues remained, and would do so for many years: The fibres in the paper reduced the image’s resolution; the process was lacking in contrast; and it was monochromatic in colour. But Talbot and his little mouse-trap cameras had created the negative-positive process which would become a world standard for over a century.

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