Is this 175-year-old image of a leaf the world's oldest photograph?
(...)
The red picture had previously been attributed to Henry Fox Talbot, who is credited with taking the world's first photographs in the 1830s.

But some believe this image may have been created in the last years of the 18th century - more than 30 years earlier.
(...)
Denise Bethell of Sotheby's said: "The possibility of a definitive conclusion regarding this early photogenic drawing is very exciting.

"We were expecting £50-£70,000 for it. If it could be authenticated as the world's oldest photograph, the sky could be the limit."
(...)
It was due to be sold again 1965