Canon Powershot S120 wlf which lets you power the

which lets you power the camera with a pair of CR123s (included) or four AA batteries

This is a genuine Asahi M42 mount reversing ring

but there's not much else out there like it

and diaphragm moves well

Canon Powershot S120 wlf which lets you power theThe Canon Powershot S120 is a very capable, pocketable digital point and shoot camera with a 5x zoom lens, 12mp sensor, manual or automatic exposure control, RAW recording, and more. It's about 85% of a G series camera, but in a much smaller package, which is pretty nice. In excellent condition, with only very minor cosmetic wear. Includes two batteries, charger, and quick start guide.