Carl Zeiss Biogon 21mm f/2.8 T

Wide but not wavey Take your favorite wide angle zoom, rack it in to it's widest angle setting, point it at a brick wall and take a picture. Make a 5x7 or 8x10 print from that file or negative and look at the straight lines of mortar between the bricks. Do they bow up? Are they wavey? Do they bow inward? Odds are they do and that's called distortion and it's the bane of all wide angle lenses. It's why the horizon line seems to bulge upward in the middle on all those vacation photos you took down at the beach or why the palm trees at the edges of the photo seem to be leaning inward like some kind of arboreal vultures. The wider the angle of view, the harder it is for lens designers to control distortion. This is especially true for SLR lenses that have to be mounted farther from the film plane than a rangefinder lens in order to create a space for the mirror to move. Now imagine a 21mm wide angle lens that weighs a couple of ounces, fits in a shirt pocket, has a fast f2.8 aperture, is autofocusing and takes photographs that show essentially ZERO distortion edge to edge. The 21mm Contax Carl Zeiss Biogon is that lens. Designed for the now discontinued but superb Contax G1/G2 rangefinder cameras it is worth purchasing one of these bodies just to be able to use this incredible optic. Mine is permanently mounted on my G1 and goes with me even on "all digital" photo trips. The whole package, lens, body and finder weigh less than any one of the lenses in my digital or film SLR kit. If a high quality, distortion free verywide angle lens is what you're looking for, you could do much much worse. The only reason I have downgraded the lens to a 4/5 is the fact that it only fits the Contax G series of cameras.Read full review

Insane Coming from Canon or Nikon? You won’t believe your eyes. This lens is as good, if not better, than anything Leica has ever made. It’s that sharp. Zero distortion. UNBELIEVABLE VALUE. How is this lens so cheap?

Excellent wide-angle lens. Small in size but good for imaging. In general, it is a good wide-angle lens for digital cameral but its imaging performance in digital camera is not as excellent as that in traditional film cameral. In modern digital camera, the lens still has a excellent high-reslution imaging in center of picture, but the marginal imaging is not so good and the red shift is really bothering.