Carl Zeiss, the giant among the optical innovations. Its designs, such as Sonnar, Planar, Tessar have been copied by other lens makers over the world. Many of today's lenses are still based on some of form of Zeiss' designs.

For people who love Zeiss, this can be both a curse and a blessing. A curse is because some of the Zeiss lenses are extremely hard to find; for someone who has collected many Zeiss lenses, not being able to get the next dream lens could cause sleepless nights. It's also a blessing because Zeiss lenses can also be cheap and easy to come by. These would the the common, but nevertheless with excellent performance for the prices that the can be obtained.

No other lens makers have their design licensed to so many other camera/lens makers. You can find Zeiss lenses in a number of mounts, from rangefinder to large formats. Names like Contax, Rollei, Hasselblad, and even a few of the Leica lenses were design/made by Zeiss.