Fast, manual-focus primes for DSLRs are popping up like mushrooms (or, in this case, truffles). The more favorably priced (Vivitar, Rokinon, etc.) may prove to be passing fads, but the made-in-Japan tanks from Zeiss should be around for the long haul. These lenses seem simultaneously cutting-edge and old-fashioned, and the full-frame 25mm f/2 Distagon T* ($1,700, street) is the latest to ride our optical bench.