The 21mm ZF lens is the unchallenged king of wide-angle lenses. The original 21mm Distagon MM is unmatched by any other SLR lens to this day, save for the Distagon ZF. Much like the 100mm ZF, the 21mm ZF’s legendary destiny is high-resolution imaging going beyond current high-resolution sensors.
Not much has changed on paper since the MM version. Glass types changed from lead-based glasses to ECO-glass, and the formula was tweaked somewhat. That belies the tremendous complexity of its design however: 26 surfaces with T* coatings, rare glass types, floating elements and internal focusing. This lens is the latest installment in an epic story in photography.
This is one review I have been looking forward to for years. I rented the lens for 2 weeks so that I could try it firsthand, but also use it as part of a major photography project. Now I don’t want to put it back in the box, I will be sad to return it.
The Distagon is a sizeable lens, even on the D700 it is not subtle. Its simple shape draws attention to it: from the slim body that suddenly flares out to a whopping 82mm filter thread to the hood’s sharp geometric angles that look like a sharp open beak. This makes the 21mm ZF somewhat of a fashion statement before it makes a photographic one. In your hands, and behind the viewfinder, the balance with the D700 is excellent and invites confidence. The total size is surprisingly similar to my previous wide-angle solution, the Nikkor 18-35mm AF-D.
Manual focus is very fast but also a bit uncertain with this Distagon. A 10-degree rotation will take you from infinity to 0.6m on this lens, a dizzyingly fast travel. The problem with this kind of speed is that the depth of field is also very significant, even at f/2.8, and it is difficult to say where critical focus lies in the frame. Architectural or landscape photographers will not mind this problem, but my journalistic style will benefit from more training with this lens.
This lens does not extend at all when focusing. If you dismount the lens you will notice the rear groups are moving into the lens as it is focused, theoretically providing better close-up performance than would normally be expected. The focusing motion is also extremely smooth and pleasant with this lens, even more so than other Zeiss ZFs.
The 21mm ZF an excellent lens to only a few caveats.
Sharpness and contrast are high over most of the frame wide-open, covering at least 70% of the area with beautifully rendered detail. Only the absolute corners are muddy at the maximum aperture of f/2.8 though even the near borders take on a slightly troubled look with a bit of an orientation preference. This performance is carried through until f/5.6 or f/8 where the entire frame is “lifted” up to essentially perfect reproduction from corner to corner. Another stop to f/11 can help to firm up those gains with more contrast at the extremes but this is picking nits, because you could convince someone that a corner crop is a center crop at any of the small apertures.
Chromatic aberration is completely absent from the images I have looked at. Thin dark branches against the bright sky can take on a bluish tint but color separation is not visible on default Lightroom conversions from RAW. Compared to the recent crop of wide-angle lenses from the big Japanese brands this is simply wonderful.
Bokeh is nothing to rave about. At f/2.8 there is a slight ringing to the circle of confusion that is most pronounced at the outer edges of the frame. This effect never really goes away but only one stop down to f/4 will take out the sharp contours and give you beautiful images in the field (the remaining artifacts being so small). Note that the circle of confusion takes on an oval shape as it moves away from the center of wide-angle lenses such as this one, smearing out-of-focus objects along the borders – I believe this effect is unavoidable but it takes some of the magic out of Bokeh.
Some may chastise me for commenting negatively on the Bokeh of a wide-angle lens because many will choose to use it only set to f/11 and hyper-focused. My personal choice of reportage style with people as subjects compels me to jump into the center of action with a wide-angle lens. This means I will use the lens nearly wide-open with a close focus distance compared to the background distance, potentially including specular highlights and point lights sources. In these conditions the lens will often reveal large-circled Bokeh, and it is good for me to know that I would enjoy its drawing more at f/4 than f/2.8.
Finally, flare resistance is on a high level but it is not immune. The full solar disk will cause some veiling and much flaring, but anything less intense (such as a foliage-scattered solar disk) will not produce visible artifacts. Flare spots are quite visible on a dark background and would be very difficult to remove. Their apparent brightness look to my eye to be 4-5 stops lower than objects lit directly by the light source - this means some photographers will never see them (in the open) while others will see them frequently (indoors, backlit by the Sun through a window).
I rented the latest 21mm Distagon to help me understand if the lens was a “nice to have” or a “must have”. My conclusion is simple: no other 21mm lens will do for me after this. I enjoyed the color rendering, the feel in my hands, the precise drawing… immediately after returning this lens I will make plans to acquire my own copy.
Would I recommend this lens to other photographers? Yes. I have no reservations, this lens delivers exactly what it promised.
I understand that many have an auto-focus or zoom bias, and that’s ok, Nikon makes the equally astonishing 14-24mm zoom for them. There is no shame in going for that other lens.
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