Spy cameras are designed to be used covertly.
“In 1886 C. P. Stirn bought the rights to make a unique kind of vest pocket camera that was...Stirn Concealed Vest Camera
“The Kiev-30 is a subminiature camera of Soviet production. For transport in the vest pocket it...Kiev-30
“The Konan-16 Automat was Chiyoda's first subminiature camera for 16mm film. Originally it was a...Konan-16 Automat
“The Japanese matchbox camera is only known from a picture and a description in the book Spy...Japanese matchbox camera
“The Kaitenkei (回転計, meaning "revolution counter") is a Japanese spy camera made by Tōkyō Kōgaku...Kaitenkei