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In the
following years, experiments on the subject were
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conducted by
Joseph von Fraunhofer (1787-1826), a German
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scientist and
Sir John Herschel, son of Sir William.
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It was Sir
William Abney, president of The Royal Astronomical
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Society and of
The Physical Society of London, who devised
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the earliest
method of direct photography far into the infrared
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region. Abney
published a chart of the infrared region of the
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solar spectrum,
and is credited with first using the term
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"infra-red," in
1880.
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After years of
further experiments, in 1904, Ben Homelike, an
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Austrian
chemist, discovered the first practical sensitizer for
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all visible
red, pinacyanol. Immediately after the invention of
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pinacyanol came
dicyanide, the first infrared sensitizer.
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