Leica’s latest 21mm ultra-wide-angle lens for full-frame Leica M-series digital and 35mm film cameras has a heritage dating back to the legendary 21mm f/3.4 Leitz Super-Angulon of the 1960s, a landmark lens based on the renowned Schneider Super-Angulon formula. However, this 8-element 7-group lens is an entirely new design that includes two aspheric surfaces and many other optical refinements not present in the original and is claimed to deliver far superior optical performance, especially at the widest apertures. Typical of current Leica lenses, it is gorgeously finished in satin black with flawlessly engraved, highly legible white-on-black scales for the apertures (f/3.4-16 with half-stop detents from f/4-16), metric distances (0.7m to infinity), and a very comprehensive depth-of-field scale. Only the footage scale is a tad less visible in orange. The focusing action is buttery smooth and well damped, with a silken precision, as well it should be on a moderate aperture prime lens that carries a price tag of $2,995, which includes an excellent screw-in lens hood, and 6-bit coding for the Leica M9. 

If you think that’s expensive, consider the alternatives. Leica’s Tri-Elmar 16-18-21mm f/4 costs $6,295, though admittedly in covers three separate focal lengths, two of which provide an even wider coverage angle, and it comes with its own universal viewfinder. The glorious 21mm f/1.4 Summilux-M, the fastest 21mm on the planet, sells for a princely $6,995 and, like the 21mm f/3.4, doesn't come with a separate optical viewfinder—a necessity if you use it on a Leica M rangefinder camera. The good news is that the accessory Leica Brightline Viewfinder may well be the clearest, most distortion free 21mm optical viewfinder ever made. The bad news is that it will set you back $759.95. Of course many folks are now mounting their Leica M lenses on compact interchangeable-lens digital cameras. Here, the good news is that you don’t need a separate viewfinder to view and compose on the LCD, but when you mount the ultra-wide 21mm on an APS-C-format camera like the Sony NEX-5N or Fuji Pro-X 1, it becomes “merely” a great 26mm wide-angle.

One of the nicest things about the 21mm Super-Elmar is its diminutive size. Without the aforementioned lens hood it’s 2.2 inches long and 2.1 inches in diameter and it has internal focusing so its length doesn't change. It definitely feels solid, but at 9.84 ounces you can't really call it hefty, and it balances extremely well on practically any camera. However, close focusing is not this lens’s forte—its minimum focusing distance of 2.3 feet will definitely put a crimp in your close-ups, but it’s great for interiors, architecture, and scenic vistas. It’s worth noting that these days when so many digital cameras deliver amazingly good noise-free performance at high ISO settings of 1600 and above, having a lens with maximum aperture of f/3.4 is seldom a serious drawback, though the super-speed 21mm f/1.4 Summilux does enhance the opportunity for pictorial effects using limited depth of field. 

Fortunately, the very best attribute of this moderate- aperture 21mm is its imaging performance, which is simply spectacular. In terms of crispness, sharpness, and its ability to capture exquisite detail, it is simply unsurpassed and may very well be unequalled—even by the 21mm f/1.4 Summilux-M, an astonishing lens in its own right. If extreme sharpness is what you’re after, you’ll get it at any aperture you choose, and this level of performance is maintained across the entire imaging field even to the extreme corners. There is virtually no color fringing or flare and linear distortion is, for all practical purposes, non-existent. In conclusion, while this remarkable lens is certainly at the upper end of the price spectrum, what it delivers may well be priceless, and that’s what makes it an excellent value for those who demand the very best.