However, its operation was something of an acquired taste, which explains the more conventional successors, the Contax II and III models. Not only was the combined shutter speed dial and film advance knob placed at the more conventional position, but it became much easier and quicker to operate. The combined viewfinder and rangefinder was not the first one on the market, but it was the first on a system camera which offered significant operational advantage, a lead ahead of the Leica until the Leica M3 of 1954.