"The 21 mm Distagon is not a newcomer but a lens with a history dating back to the Contax C/Y era. The lens was one of the latest additions to the system (discontinued just after the Millennium). Soon after its release the news spread that this lens is something special - user comments and reviews suggested that it was the best mass production ultra-wide lens ever produced. Due to the rather mediocre alternatives in the EOS land some Canon users were even desperate enough to use it via adapters on their EOS cameras ... and to pay more for it over at ebay than its original MSRP. At the peak of this crazy hype it was almost more an investment rather than a purchase.
Well, these times are over because Zeiss did eventually listen and the lens is available again for Canon (ZE) and Nikon (ZF, ZF.2) cameras. There also was a K-mount version for Pentax cameras (ZK), however Zeiss decided to discontinue the ZK-line in 2010.
The new Distagon is not 100% identical to the original design. According to Zeiss it has been modernized with respect to flare and environment-friendly glass and the optical design has also been altered slightly. This price has not changed though - at around 1500EUR/US$ it is still not exactly a cheap item.
The Distagon is a full frame lens (all ZF lenses are), however in this review we'll have a look at how the lens performs on our current DX test camera, the Nikon D7000, where it resembles a moderate wide angle lens."
Via
Philippe Gassmann