Carl Zeiss Distagon T* 28mm f/2.8

Introduction

Carl Zeiss Distagon T* 28mm f/2.8 is a classical manual focus Zeiss lens for the now defunct Contax/Yashica mount systems. The Contax line of cameras and lenses was discontinued in 2005 after Kyocera, which jointly owned the development rights for this brand, has decided to shutter its camera business. As of mid-2008, Carl Zeiss has not yet announced any official plans for the Contax brand name, although the company hinted that they will eventually bring this great brand name back to the market. After discontinuing the Contax lineup, Carl Zeiss was left with a hole in its SLR business. This changed in early 2007, after the company announced introduction of Carl Zeiss lenses for Nikon F and M42 universal screw mounts. Shortly after, the company also introduced support for the Pentax K mount. And in late 2007 the company finally resurrected its 28mm Distagon.

Like most Contax branded lenses, Carl Zeiss used to manufacture Distagon T* 28mm f/2.8 in two variants - AE and MM. Both types were manufactured in Germany (by Carl Zeiss itselft), as well as in Japan (by Kyocera). The lens is more or less readily available on used markets like eBay, with good quality Japanese manufactured MM versions of the lens fetching ~US$300, while good quality German manufactured MM versions go for as much as US$400. The new version ofthe 28mm Distagon, which is by the way is manufactured by Cosina of Japan, Carl Zeiss Distagon T* 28mm f/2 in ZF (Nikon F) or ZK (Pentax K) mount cost ~US$1,000 - almost 3x of the used copy.

The optical construction of the lens consists of 7 elements in 7 groups. The lens is very light and compact, measuring only 6.2x5cm (2.4x1.9in) and weighing 280g (9.9oz). The build quality of the lens is quite good - similar to other Contax lenses, Distagon T* 28mm f/2.8 has a fully metal barrel and aperture ring, with a nice rubberized focusing ring. The focusing ring rotates very smoothly and the aperture has a nice feel to it - there's no play whatsoever and the ring locks into positions with a nice, satisfactory click. Despite its lightweight and compact construction, the lens leaves the impression of being pretty sturdy. While the inner cam of the lens extends slightly during focusing, the front element does not rotate at all, which allows using circular polarizers with this lens. The lens accepts 55mm screw-in type filters and has the minimum focusing distance of 25cm (10in) and the minimum aperture of f/22.

Image

To test the lens on Canon cameras, I used a generic Contax/Yashica to EOS adapter without AF confirmation (if you plan to use the lens extensively, consider buying an adapter with AF confirmation). Keep in mind that you will be limited to operating your camera either in fully manual or aperture priority mode when using a Contax to EOS adapter. On APS-C camera like Canon EOS 400D (Digital Rebel XTi) used for testing, the field of view of the lens resembles that of a 45mm lens on a full-frame camera (and thus robbing you of the wide aspect).

 

Summary
Lens Composition 7 elements in 7 groups
Angular Field 74 degrees
Minimum Focus 25cm/10in
Focusing Action MF
f-stop Scale f/2.8-f/22, manual
Filter Size 55mm
Lens Hood G-12 soft hood or No.1 metal hood
Weight 280g/9.9oz
Dimensions 62.5x50mm/2.4x1.9"
Lens Case No.1 (included)

 

Field Tests

Carl Zeiss Distagon T* 28mm f/2.8 showcased exceptionally good behavior in the field. The lens produced very sharp and balanced results across the aperture range. Center performance was easily one of the best in this class, and border image quality was very solid in general (a little bit of weakness at f/2.8, but still not disastrous and often not even noticeable in many frames).

Like any manual focus lens used on a non-native body, Carl Zeiss Distagon T* 28mm f/2.8 was a pain to focus. This is not necessarily the problem of the lens itself, but rather a characteristic of most modern cameras. Unlike the old times, when SLR cameras had focusing screens that incorporated focusing aids (i.e. a split circle), majority of modern dSLRs have auto-focusing systems and hence don't include screens suitable for manual focusing. Combine that with often smaller viewfinders and the need to use stop down metering for using a non-native lens, and quite a few people might get repulsed by the whole idea of an alternative lens/camera combination. If you belong to such a group, I'd recommend getting an AF-chipped adapter, which would allow your camera to retain focusing confirmation. You will still have to manual focus the lens, but the camera's AF system will clearly indicate when the target object pops into focus. Also keep in mind that because the lens offers a pretty large field of view, small focusing errors are likely going to be masked. I often used hyperfocal distance focusing with Carl Zeiss Distagon T* 28mm f/2.8 and managed to achieve pretty good overall results, although it's worth mentioning that this method will not necessarily produce the best results at close distances.

 

ISO 400, 1/400, f/2.8, 28mm (Canon 5D)
ISO 400, 1/400, f/2.8, 28mm (Canon 5D)

Carl Zeiss Distagon T* 28mm f/2.8 did not show any particular strength in bokeh handling. OOF highlights were pretty harsh, with well defined highlights around borders. Contrast transitions around OOF objects were somewhat harsher then one would desire. On a slightly positive note, the lens did not exhibit any double edging around OOF objects.

 

Vignetting @ f/2.8 - full frame vs 1.6x crop
Vignetting @ f/2.8 - full frame vs 1.6x crop

The lens produced moderate, but noticeable amount of vignetting on a full frame Canon 5D at f/2.8. Wide angle lenses are prone to this artifact and Distagon T* 28mm f/2.8 is not an exception here. Vignetting still persists at f/4, albeit at at a lower level and by f/5.6 it is practically non-existent. Vignetting on an APS-C camera was significantly lower - at f/2.8 it was already minimal and at f/4 it was pretty much gone.

The lens held up very nicely against flare, even at the widest aperture, and did not show any major distortion. Color rendition, a playground typically dominated by Leica lenses, was pretty accurate - I literally did not see a single shot that required post-processing color adjustment. The lens produced images with good amount of contrast and well saturated textures. Chromatic aberration, where Zeiss lenses typically excel, was not visible in most frames.

 

ISO 100, 1/1000, f/2.8, 28mm
ISO 100, 1/1000, f/2.8, 28mm

 

Lab Tests

Please note that MTF50 results for APS-C and Full-Frame cameras are not cross-comparable despite the same normalized [0:1] range used to report results for both types of cameras.

 

Canon APS-C: The lens performed exceptionally well in the lab, producing very balanced overall results in the center and around borders. You will notice from the MTF50 charts that the lens is tack sharp with (marginally) best results at f/4. There is a little bit of degradation in image quality at f/11 (both in the center as well as around borders) due to the diffraction effect, but the performance is still very solid. You would be able to get outstanding 19in and very decent 24in prints with this lens pretty much across the entire aperture range - a record in its own right for a wide-angle lens. Conclusion? The results as impressive as they are unique - not that many 28mm primes produce such a consistent and impressive performance.

 

MTF50 (Line Width/Inch on the Print) @ 28mm
MTF50 (Line Width/Inch on the Print) @ 28mm

 

Normalized raw MTF50 @ 28mm
Normalized raw MTF50 @ 28mm


Chromatic aberration (fringes of color caused by sharp transitions) was negligible, practically non-existent across all tested apertures - this is a signature aspect of Zeiss lens design so it is often expected by default but nevertheless should be valued accordingly.

 

Image borders @ 28mm (100% crop): f/2.8 vs f/8
Image borders @ 28mm (100% crop): f/2.8 vs f/8

Canon FF: The lens shows pretty solid overall performance on a full frame Canon 5D. Center performance is exceptionally good straight from f/2.8. Border quality is lagging a bit, especially at the widest aperture setting, where quality is kind of average (but not disastrous by all means). Fortunately, quality improves very quickly with stopped down aperture - by f/4 it becomes very solid and by f/5.6 outright exceptional. Conclusion? While border performance at widest aperture level on a full frame camera is not as good as on an APS-C camera, the lens performs better then most wide angles out there and showcases pretty good overall performance.

 

MTF50 (Line Width/Inch on the Print) @ 28mm
MTF50 (Line Width/Inch on the Print) @ 28mm

On a full frame Canon 5D chromatic aberration was practically non existent in the center, averaging ~0.2px across the tested aperture range. CA around borders was slightly higher, averaging ~0.8px at f/2.8 and dropping to ~0.5px once stopped down to f/4 and beyond - quite a low level for a wide angle lens.

 

Image borders @ 28mm (100% crop): f/2.8 vs f/8
Image borders @ 28mm (100% crop): f/2.8 vs f/8

Alternatives

There are obviously quite a few 28mm primes available on the market, so the easiest place to start is with other Contax branded Carl Zeiss lenses. The first lens that comes to mind is the 'Holliwood' version of the Carl Zeiss Distagon T* 28mm f/2. This lens generates quite a bit of controversy among users, with some claiming it to be a much more capable then its slower f/2.8 variant, while other claim that it's not that special. In either case, the lens is pretty hard to find these days in good quality, so expect to pay north of US$800 for one. If you're willing to consider slightly shorter or longer lenses, then it is worth taking a look at Carl Zeiss Distagon T* 25mm f/2.8, Carl Zeiss Distagon T* 35mm  f/1.4 and Carl Zeiss Distagon T* 35mm f/2.8. As mentioned above, Carl Zeiss is currently manufacturing a number of SLR lenses for Nikon F, Pentax K and M42 universal screw mounts, so it might be worth examining the newest additions as well, including Carl Zeiss Distagon T* 25mm f/2, Carl Zeiss Distagon T* 28mm f/2 and Carl Zeiss Distagon T* 35mm f/2. Outside of the Carl Zeiss lineup, Leica's Elmarit-R 28mm f/2.8 (the latest version) and Summicron-R 35mm f/2 (also latest revision) are excellent performers. Finally, Nikon's old, now discontinued Nikkor 28mm f/2.8 AiS lens is an excellent value, price/performance wise.

 

Recommendation

Carl Zeiss Distagon T* 28mm f/2.8 is clearly one of the better 28mm prime lenses out there. The lens offers excellent image performance, combined with good handling of artifacts like chromatic aberration and distortion, and excellent build quality - all that at a very reasonable price. If you're a Contax system owner, then this lens is probably one of the crown jewels of your lens collection. And if you're considering an alternative mount 28mm prime, then Distagon T* 28mm is unlikely to disappoint you. Obviously you should be comfortable handling manual focus lenses, otherwise you'd better stick with the native lenses.