PHOTOOG Photography writings by Olivier Giroux

12Dec/1018

Carl Zeiss 2/28 Distagon T* Review

The 28mm Distagon ZF is the best kept secret of the ZF lens program. Overall it is a powerhouse of a lens, with particularly excellent treatment of color, but some issues at full aperture have kept it in the shadow of more consistent lenses in the series. This Distagon is an excellent choice for a normal lens on APS-C cameras and a demanding (but rewarding) high-speed wide-angle on full-frame cameras.

This Distagon is quite closely related to its Contax predecessor, one of the pioneering designs for floating elements in wide-angle designs. The new design improves performance at the maximum aperture substantially while keeping other parameters largely unchanged. As a result the new lens inherits high and low points from the advanced Contax design.

The 28mm Distagon ZF was a happy surprise for me. I delayed testing it because I anticipated problems and enjoyed my 35mm Distagon too much to feel the need to overcome them. In the end I enjoyed this lens a lot and can now imagine using it in addition to, or even in place of, a 35mm Distagon.

Once again I want to thank Roger at LensRentals.Com for allowing me to review this lens. Double thanks for letting me hold on to the lens for an extra week.

Operation

The 28mm ZF is of average size and weight for a ZF lens. As in almost all things, it sits between the 35mm and 25mm lenses and could easily be confused for either by sight or by touch (I made this mistake at least once). Like these other lenses on the D700 the combined pair is slightly rear-heavy but comfortable, and far more portable than most other lenses.

Manual focus is quick and decisive with this lens, with a rate of focus that is ideal for use in photojournalistic use. Unfortunately at full aperture accurate placement of focus for emphasis in the other regions requires special attention and skill, due to (very) strong field curvature. This issue is compounded by the poor quality of the D700’s manual focus assistance in the outer regions.

The 28mm ZF extends slightly when focusing. A floating group at the rear helps to maintain image quality in the close range, down to 0.24 meters.

Drawing

The 28mm ZF draws outstanding colors, at times giving you the impression that you are shooting at the golden hour while standing in middling afternoon Sun. Besides its great color output, the 28mm ZF is a high performance lens with one key flaw: it exhibits strong field curvature. For this reason (mainly) its other strong suits are only revealed at smaller apertures.

Wide-open sharpness is high and micro-contrast is good (but not great) over almost the entire frame. This is a little-known fact which is revealed by careful focus in live-view mode, but is well hidden in actual use due to large amounts of field curvature.  Obviously this fact is also hidden in laboratory tests that use flat resolution charts.

More typically, and under test conditions, only the central region of the frame (or the selectively focused region) has high sharpness and good micro-contrast at the maximum aperture. The outer (or other) regions then are drawn in defocus and with strong aberrations (coma and astigmatism) that further degrade image perception.

Stopping down to f/2.8 improves micro-contrast to excellent levels over a good portion of the frame -- in fact this lens thus produces some of the best micro-contrast I’ve seen yet! This stop also mitigates field curvature for many uses on full format sensors. On APS-C sensors image quality should be unreservedly excellent starting from this aperture.

Stopping down further to f/4 improves image quality at infinity on full format sensors, which now suffer very little from field curvature, and then not at all at f/5.6. Image quality at f/5.6 is excellent for all uses on all cameras.

Outside the (curved) plane of focus, aberrations play various roles against image quality. Coma, astigmatism and longitudinal CA combine to produce some very ugly Bokeh at times – this is one lens which does not pass the “backlit foliage” test for example. This is something to be aware of and can be a problem, but luckily stopping down to f/2.4 or f/2.8 improves things dramatically. Bokeh quality becomes very high around f/4.

Lastly, the 28mm ZF is a poster child for the extended Zeiss T* family of lenses when it comes to color and global contrast. Resistance to veiling glare is high. Resistance to internal reflections is good – though it can produce curious looking flare spots against the Sun.

Conclusion

The 28mm Distagon ZF is often overlooked because of its reputation for high levels of field curvature that reduce its effectiveness at f/2 on full-frame sensors. There is no denying that this is a low point for the lens, but with so many high points there is much to redeem it also. At the very worst, one could think of it as a splendid 28mm f/2.8 lens.

Would I recommend this lens to other photographers? Yes. Especially APS-C users.

Samples


Comments (18) Trackbacks (0)
  1. I begin to like your blog more and more Oliver! Really great how you publish all these tests of my (to-be) favorite lenses :-P. Thank you for this one!

    I am wondering however about the filed curvature “issue”.
    As far as my knowledge goes field curvature is not changing with the aperture chosen. It is just that it “disappears” in the increased DOF when using smaller apertures. It is also something very common in Wide Angle-lenses. And, invariably, it is detected on testwalls (that are very flat, to their nature) but not very often complained about by actual users of the lens as in real life you seldom photograph a flat surface at the widest aperture.

    Furthermore I read in your report that the field curvature is disappeared when you stop down one stop (to 2.8). This leads me to believe the field curvature may be severe but not more severe then in many other WA-lenses.

    Could you maybe elaborate a little more on how detectable the field curvature issue is in real life photography? What is your experience in this?

    Most obliged,

    Kind regards,

    Marc-paul

    • Excellent questions.

      Field curvature is common in wide-angle lenses, yes, but those which have achieved high reputations in the public eye tend not to have too much of it. For example, the 21 Distagon doesn’t struggle too much with it. The 35 Distagon is closer to the 28 Distagon and doesn’t suffer from it either. If you are a wide-angle enthusiast you are likely to gravitate towards wide-angle lenses without much field curvature, even if you aren’t completely conscious of it.

      Field curvature is not a problem in real-world use *if* you are able to focus reliably off-center. Personally I find focusing via eyeball pretty difficult in all but the most ideal conditions. Hence I rely a lot on the D700’s electronic rangefinder even in dynamic conditions — but now unfortunately the AF sensors that are on the periphery of the D700’s AF grid are kind of crappy. So you have to juggle a combination of three tough breaks here : (1) eyeball focusing is hard, (2) off-center points suck and (3) the center point can’t be used due to field curvature.

      Field curvature has the effect of placing a subject that should be in focus into a zone of defocus. By this fact then it’s obvious the object will not only be blurred (naturally) but also suffer from aberrations that affect more strongly zones of defocus. Coma and astigmatism have particularly bad effects here. What I’m saying in my review is that the jump from f/2 to f/2.8 does both increase depth of field and reduces aberrations — the combination of the two leads to major improvement in subjective image quality in the affected regions.

      All of this is in the context of people photography, which is a pretty soft and flexible type of photography (just land some sharpness somewhere in the face). Other kinds of photography variably don’t care at all or care so much that no work can be done with a lens that has field curvature.

      You’re most welcome Marc-Paul,

      Olivier

  2. THX again Oliver for the extensive answer!

    I was struck by your statement about the focus of your D700. You also mentioned this in the review but I had not realized what exactly you said.

    If I, with my D300, mount a ZF.1 lens then the only AF focus point I get in the viewfinder is the center one. Is this different in the D700? Or is this some setting I can manipulate so I can use multiple focus points?

    Sorry for my ignorance.

    Greetings,

    Marc-paul

    • I can select any AF point in the grid with the cross pad, like normal AF operation. I’d be surprised if that was a special feature of the D700. Make sure to unlock the pad or nothing will happen when you use the pad.

  3. You are correct Oliver. It works with the D300 too. THX for the info.

    • It occurred to me after writing my before-last reply that one reason the D700’s off-center points are struggling with the 28mm Distagon is probably that coma and astigmatism screw majorly with phase detection.

      If you think about it, the phase sensors are attempting to collect a 3D measurement of the travel path of light rays, under the assumption that light rays neatly converge towards the plane of focus. As the cone of rays is distorted outside the plane of focus by coma/astigmatism, it must be extra hard to guess the placement of the plane of focus.

      Incidentally I remember the D700’s struggling to focus off-center with the 70-200VR (v1) which also had high astigmatism. That’s compatible with my hypothesis at least.

  4. Makes sense, Oliver. It may also be due to the fact that the sensors off-the center around the edges of the VF are no cross-sensors that are relatively easily fooled.

  5. i have a Nikon 28/2 AI-converted which is (surprisingly) one of favorite lenses to use on my D700 and m4/3 cameras. The only thing that’s sort of a bummer with this lens is that f2 has veiling/CA that it decreases contrast and perceived sharpness.

    I am seriously looking at replacing this with the Zeiss 28. I couldn’t care any less about the “field of curvature” issue (which is blown out of proportion, IMO), my only concern is if it doesn’t have the veiling issues at max aperture (that’s the price difference I’ll be paying for, after all)…if there is virtually no decrease in contrast/sharpness from f2.8 to f2 (I couldn’t search a lot of sample shots @ f2.0) then i guess i will have to sell my right kidney (already sold the left one for the D700 LOL)

    • The 28ZF doesn’t veil easily at any aperture. As for micro contrast it depends on your expectations, but if you hadn’t seen what it (or its sisters) can do at smaller apertures you might think wide-open was pretty good in that regard.

      It’s always hard to tell people that they should buy X over Y, or that they will like Z. The 28ZF is probably a good fit for you, it does well in the areas you want improved.

  6. I got this lens recently and seem to be falling in love with it. I like the color it produces. The sky somehow renders bluer with this lens. The 28mm ZF.2 compliments the 50mm MP ZF.2 well. I use both these lenses on the D700.

    And an excellent review!

  7. Hello Olivier,

    I read this just now because I “thought” i have made a wrong decision to have bought the Zeiss Distagon 28mm F2 ZF. I did not choose the 35mm. There are numerous reviews on how bad the 28mm is; with so many problems at wider apertures especially on Full Frame. I am using a D700.

    From my research (only after buying it); it seems that the sharpness of 35mm is much much better. Is this so? Did I make a wrong choice? How can I make better images with the way you describe about this 28mm using D700?

    I think I need some encouragement!

    Appreciate your insight!
    Michael.

    • Hi Michael,

      This lens is one of my all-time favorites. The color it produces is fantastic and is well worth working around the a issues.

      Like any piece of equipment you have to be able to identify the situations when it will not work as you desire, and know what to do to avoid it. Like most lenses the way to avoid issues is to stop it down. Like many fast wide-angle the bad situations are those with busy/nervous high-contrast backgrounds.

      The 35mm isn’t sharper, nor does it have better micro-contrast than this 28mm, this lens is better on both. What the 35mm has is a lot less aberrations in the image periphery, and from that there are fewer cases when you must stop it down.

      Olivier

  8. Thank you Olivier!

    This 28mm is actually my first Zeiss as I am very much attracted to the color rendition & 3D effect of the Zeiss images from the internet. I do not know why I ended up with 28mm & not 35mm though. May be I like the artistic effect in addition to the color & sharpness of Zeiss.

    May I ask you, if I would like to buy another Zeiss ZF, which one would you recommend? I already got a Nikon AFS 50mm 1.4G & I feel that 28mm is a little wide to shoot people. Would you think I should get a 35mm (but the focal length is too close to my 28mm; will people buy two very close focal lengths) or the 100mm Makro as I read from your review that it is superb!

    Michael.

    Michael.

    • There are many very personal options possible.

      A pairing of 2/28 and 2/50 is what I use nowadays, on my main camera the Leica M9. I’m very happy handling just these two focal lengths for virtually any assignment I give myself. The 1.4/50 ZF is cheaper, smaller and less good than the 2/50 ZF – but in my opinion just good or better value.

      A pairing of 2/28 and 1.4/85 is I think a kind of powerhouse duo. I wasn’t able to take bad pictures with either lens. Relatively speaking; the hit ratio was very high is what I mean. I think the rational artist could very well pick this option and shock all his/her entourage with glorious imagery.

      The 2/28 and 2/100 are too far apart in my opinion, but I shot 2/35 and 2/100 on my D700 exclusively for over a year and rarely wanted for something else. The 2/100 is going to be historically significant, there’s just a handful of lenses that come out per decade that will be remembered into the next several decades, and this is one those for our present time. If you feel like going this direction you’ll need something in the middle, the 1.4/50 is a good choice for that.

      Bottom line — given that you have a 1.4/50G already I would point you at the 1.4/85 or 2/100. Extremely different lenses though. Both reviewed here.

      Cheers,

      Olivier

  9. Hello Olivier,

    Thanks for the great Zeiss reviews! There are relatively so few reviews of the lenses online, your reviews have been very interesting and useful. I have a question I am hopeful you can help me with:

    I have a Zeiss 2,8/25 ZK, which I love shooting with, especially due to its versatility of close focus and landscape possibilities. I wish to add another Zeiss lens, and I’m thinking of something in the “normal” range, thus the choice on the crop Pentax sensor would of course be the 2/28 or the 2/35.

    My question is, how would you characterize the rendering and overall performance of the 35 and 28, relative to the 25? I keep reading of the artistic vs reporter comparison between the 28 and the 35, but how similar is the rendering of the 25 to the 28 or 35? Putting aside the focal length differences, if you were in my position (with the 25) and wanted a normal lens that had different rendering, which lens would you recommend?

    Thanks in advance for your response,

    Justin

    • Hi Justin,

      Your 25mm is a normal lens, in the sense I take it to mean. It’s a 37.5mm-e which puts it in that 35-85mm family of normal lenses.

      A 35mm-ish lens is perfect for just about everything, i’ve shot ~18000 images with my 35mm lenses and keep shooting more. You don’t want another lens that’s too close to that focal length, one lens in the near-wide/normal range is enough, go for at least 50% different.

      So my advice is certainly against the 28mm. It’s a really lovely lens, I’d recommend it to anyone who doesn’t already own a 25mm. For you, there is just not enough differentiation between the two to make sense to own both.

      I absolutely recommend the 35mm lens. I would also recommend you at least think of getting something longer, like one of the 50mm, to end up with a pair of 37.5mm-e and 75mm-e in a two-lens bag. That is a really fantastic pair for shooting human subjects, or just life in general.

      Cheers,

      Olivier

  10. Thanks Olivier.

    You’ve confirmed what I am thinking, that 28 really is too close to 25, and the difference in “drawing” between the lenses is not sufficient to have both.
    I actually have quite a couple of lovely Pentax lenses in the “normal” range, but wanted to get a Zeiss to complement, and perhaps replace them.

    Thanks again,

    Justin


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