Why aren t cameras and lenses from different manufacturers interchangeable?
Each camera maker wants to lock you into their system. They don t want to see sales lost to people buying other makers products. So they design their own lens mount systems which other makers don t or can t use. This also lets the manufacturer unilaterally alter the lens mount design to add new features without the need to consult with a committee or other makers. This is why a Nikon F lens cannot fit a Canon EOS camera. And why a Pentax K lens can t fit a Sony SLR camera body. Of course, some third party makers build lenses which fit different camera systems, but they do so only by producing different versions of each lens for each camera system. In the 1960s and 70s many makers used 42mm screwmount lenses of the type popularized by the Asahi Pentax Spotmatic camera. Back then lenses lacked complex computerized autofocus systems and the like, so it was comparatively easy to make them. That s probably the closest the world has ever come to a universal lens mount system. Interestingly,
