PHOTOOG Photography writings by Olivier Giroux

23Sep/105

Carl Zeiss 2.8/25 Distagon T* Review

The 25mm Distagon ZF is a typical wide-angle lens on paper, conservatively specified and priced. In practice it is a versatile lens that could be recommended to many who wish to concentrate on their photography skills. For various reasons the appeal of this Distagon is centered on APS-C cameras where it offers a handy field of view, delivering much the same experience as the 2/35mm Distagon ZF does on full-frame cameras.

The design of the 25mm ZF does not appear to be a refinement of the previous Contax 25mm design, but rather a fresh start for Zeiss and this focal length. The Distagon name is associated with retro-focus lenses, such as this lens is, and suggests that geometric distortions may be a challenge for this lens. Based solely on the charts, it looks as though APS-C users may be less affected by the distortions as the dreaded “mustache” effect comes into play only in the outer regions on full-frame sensors.

I recently discussed this site with Roger at LensRentals.Com and he generously offered to send me a copy of this lens for review. The lens I received from LensRentals was in the same condition that all of LensRentals’ lenses are, in my experience as a customer, which is to say immaculate and looking like new. Even though my time with the lens was shorter than usual, I was able to do three solid shoots with it, including a full day of journalistic coverage at a technology conference in Silicon Valley.

Operation

The 25mm ZF is slightly shorter than the 35mm ZF but looks otherwise identical to its sister lens. It is slightly larger than the only other similarly-specified lens, the ancient Nikkor AF 24mm f/2.8D, but in use the size of the ZF feels just right. On the D700, or most of Nikon’s DSLRs, this is a compact lens that compares well to the massive AF-S 24-70mm f/2.8G zoom at this focal length.

Manual focus is fast with this lens but precision is a real challenge. As with the 21mm ZF, the significant depth of field with a wide-open aperture makes it difficult to tell where the plane of critical sharpness lies. A viewfinder magnifier or a viewfinder with greater native magnification is necessary for precision work.

The implementation of focus in this Distagon offers one surprisingly useful feature : a maximum reproduction ratio of 1:2.3. This is nearly the same as the macro lenses in the ZF lens program, which I think should merit this lens the nickname “Makro-Distagon”. Sadly the reproduction ratio is not marked on the lens barrel as with the Makro-Planars, so you are left guessing at the distance needed to achieve a particular frame coverage.

The Distagon extends while focusing, quite significantly so at the closest focus distance, and all the elements move as one. Hence despite the unusually large reproduction ratio, this lens is not equipped with floating elements to correct for close focus conditions. Note, the 21mm ZF offers this feature despite a much lower maximum reproduction ratio.

Drawing

Zeiss overstates the performance of the 25mm ZF somewhat by using the term “legendary”, but it is still quite a good performer. In my opinion the 25mm ZF delivers 3/4 what the 21mm ZF does, for roughly 1/2 the price, and in 1/2 the size. In terms of resolution on full-frame sensors this ZF is roundly outclassed by its properly legendary sister lens, but can still deliver truly excellent results on APS-C sensors.

Sharpness wide-open is good with fine detail at high contrast in the center portion of the frame. Except for the outer zones on full-frame sensors, there is little incentive to stop down as the performance is high from the start and does not improve much at smaller apertures. These outer zones show poor detail and contrast at full aperture however, and only small incremental improvements come here with each aperture stop until the peak around f/11 (the diffraction limit).

Lateral chromatic aberrations are low across the frame, but if you try your hand at macro-photography with this lens you may notice some longitudinal chromatic aberrations. These are also present on the larger Makro-Planars and go away at smaller apertures. You may also want to use smaller apertures to reduce the appearance of light fall-off, which is pretty significant with this lens at full aperture.

Bokeh is generally good with the lens, but the uncorrected astigmatism revealed by the published MTF charts takes its toll. In some images the defocused background will look smeared, rather than confused/blurred.

Conclusion

As paradoxical as it may sound the 25mm ZF is the “value” wide-angle lens in the ZF line-up, in a sense similar to the 1.4/50ZF which it complements very nicely. In a nutshell it offers less thorough performance than some of its sister lenses, at a lower price and with lower bulk. APS-C users should rejoice however, because they will see comparatively higher and more even performance with a field of view that is relatively more useful than full-frame users will.

Would I recommend this lens to other photographers? Yes. Much more enthusiastically so for APS-C than full-frame users however. Full-frame users should first look at the 21mm ZF.

You can rent the copy of the lens used for this review (a ZF.1 version) from LensRentals.Com.  You can also buy the 25mm ZF at B&H.

Samples

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Comments (5) Trackbacks (0)
  1. As your review suggests, this lens is much better than the reputation it has acquired. Its reputation is tarnished by poor sharpness and strong field curvature at close range, where test charts are typically shot, and where Zeiss suggest this lens might be used.

    It focuses down to 0.17 metres, which is probably not coincidental: the “legendary” Distagon 25 mm f/2.8 for Contarex cameras also focused down to 0.17 m. However, in the early 1960s photographers were a tad less critical of image quality than they are today. For one thing, they hadn’t been exposed to Nikon’s CRC tech. It was either brave or foolish of Zeiss in the noughties to provide focusing down to 0.17 m with this unit-focusing retrofocus design.

    Still, the lens has oodles of character and is delightfully compact by modern standards. It also has excellent flare resistance (read: rich colour) and pretty nice bokeh by my standards, though I can’t disagree with your “smeared” comment. The build quality is as good as anything these days, though perhaps not quite up to the lofty standards set by Zeiss, Nikon, Pentax, etc. in the past.

    It’s nice of you to offer a fairly generous appraisal of this relatively humble offering from Zeiss. I’ve liked the idea and execution of the 25 mm Distagon ZF since it was introduced, but it seems people just don’t appreciate its strengths! Perhaps impossibly good f/2.8 standard zooms like the 24-70 mm Nikkor AF-S have made people suspicious of f/2.8 primes that aren’t optically much better. That’s a shame.

  2. As the proud owner of this lens (exclusively used on an APS-C D300 and a full frame FM3a -with B&W sensor in it ;-)) I can follow the remarks Oliver makes here. There is, however, a but…. A big one….

    And that is that this lens renders beautifully! Very beautiful! Each and every shot I make with it is just fantastic and is easily recognizable by its beautiful drawing of reality. I often use it very close but not for photographs of test charts but real life samples. And there the curvature of field is not a big problem.

    In short, I like this lens as much as I do the ZF 35/2 and only a little less then I like the ZF 50/2 and 100/2. If you do more then just taking pictures of test charts and you want pin sharp pictures with beautiful colors and fantastic rendering of reality this is your lens. Do not hesitate to get it!

  3. A nice summary of the lens. The comments from Specularist and mpve are appreciated too.

    I have so often heard the phrase ‘a waste if not used on full-frame’ regarding wide-angle lenses. It was a nice change to gather a couple endorsements for using this glass on APS-C bodies.

    My greatest hesitation investing in wide angle lenses is the inability to verify edge uniformity/sensor alignment on a crop-factor DSLR. Testing this would be tricky using the 2.8/25 due to field curvature (as mpve pointed out). The difference in image character may be negligible in actual 3D images, but these nagging insecurities are still important for those who plan to move up to a full frame sensor.

    • Hi Matt,

      If a full-frame sensor is in your future then you probably want to try another lens. Sadly the 2.8/21 is quite a bit more imposing for a lens so it’s not such an easy replacement.

      If you aren’t looking for all-manual lineup, and particularly if you’re not yet invested in Zeiss, then I would recommend the 24mm Nikkor. It’s the most fun lens I have used recently.

      Olivier

  4. I use this lens in a d800. Against the nikkor 24-70 f2.8, i cant say it is sharper than the nikkor at 24mm. Where this lens comes into its own is the “zeiss” colors and drawing. Also the incredible closeup focus makes the lens versatile. I am very happy with this lens and not worried about any so- called technical defects


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