Many old cameras require batteries that are no longer manufactured. This link has a nice chart of cameras that use a particular type of old mercury cell called the PX625. Such as the Yashica 124G, Leica CL, Konica Autoflex, etc. So if you have one of the cameras on the chart look for adapters like this one to allow you to use new fresh batteries. (I haven’t used this adapter yet and can’t vouce for it. If you’ve used it let me know.)
You’ve heard about Camerapedia right? Well if you haven’t it’s like wikipedia for old cameras. A great way to learn about that old camera you found at a yard sale. So much amazing information!
The history of the Kardon camera is a story of forgotten American genius. The Kardon camera, manufactured in several variations from 1945-‘54 represents an important American contribution to the then-state-of-the-art “miniature” camera. And it represents Peter Kardon’s patriotic effort to answer to the US military’s need for a high-quality 35mm camera during World War II. The Kardon camera was a technical success, and a financial failure, whose last remnants now, after 60 years, reside in my camera shop.