Contessa Nettel Cocarette on the Sony DSLR A100
A Contessa Nettel Cocarette camera attached to my Sony DSLR A100 by means of sticking an 11mm M42 extension tube to the rear port of the camera. The moving lens assembly allows infinity focus to be achieved, enabling the 105mm f/4.5 Carl Zeiss Tessar lens to be utilized with the DSLR. (Or indeed, almost any SLR capable of accepting M42 lenses either directly or with an adapter...)
See this image for details about the camera and the modification.
P. S. The camera has not been damaged in any way; no hole has been drilled (there's one already there) and the modification is completely reversible. The camera can still be used to shoot film even with the modification in place (just put a rear cap on the extension tube).