George Pek already can name the woman in this paper print, which he bought 21 years ago. According to the caption, she's Judith Simpson, aged 74 when she had her picture taken in 1848. Although he's identified the subject, Pek wants to know what type of photograph he owns and where it was taken.

I love a good photo mystery, and this picture was a real stumper. It offers a rare look at an early photographic method. I haven't been able to answer all of Pek's (or my own) questions about the portrait, but here's a start.