When Leica ushered in the era of 35mm photography over a century ago, it did not immediately offer a coupled rangefinder (that came in 1932). Precise focusing was difficult with early Leica cameras, so other companies filled the void and offered useful accessories to early photographers. A particularly cool, stylish example is the Kühn Flexameter designed for Leica cameras. As photographer Mathieu Stern shows, the Flexameter is a brilliantly-engineered camera accessory. Given its heritage, it is little surprise that it was good for its time, considering it was invented 94 years ago. Kühn was formed by husband and wife Kurt Kühn and Elsie Leitz-Kühn, daughter of then-Leica president Ernst Leitz II. Although not the topic of this story, Ernst Leitz II and his daughter, Elsie, were instrumental in organizing the Leica Freedom Train that helped save hundreds of Jews from Nazi persecution in Germany. Elsie was also an important figure in the development of the Flexameter.…