Carl Stormer (1874-1957) was a Norwegian geophysicist, mathematician, and aurora researcher who used a (at the time) cutting edge spy camera to take secret photographs of people in the 1890’s.
He got this C.P. Stirn Concealed Vest Spy Camera in 1893. There are more than a hundred glass plates known with photos made by his camera. Here are some examples:
Here’s some random girls in Oslo. Stormer took these candid shots in Oslo, Norway between 1893-1897.
This is Kristian Birkeland, future teacher and coworker of Carl. He used to be on the Norwegian 200 krones note.
Henrik Ibsen, major 19th-century Norwegian playwright of realistic drama.