Carl Zeiss 100mm f/2 Makro-Planar T* 2/100

(From Carl Zeiss lens literature) No other lens currently combines such a high maximum aperture with such outstanding image quality from infinity to half life size (1:2). This level of performance makes the lens perfect for situations that require greater distance from the lens. Precision focusing makes it easy to achieve extraordinarily selective image sharpness for the key elements of the subject.

SLRgear Review
May 25, 2008
by Andrew Alexander

Carl Zeiss produces two macro lenses in its ZF series: the 50mm and the 100mm. The 100mm ƒ/2 model is available in the Nikon F-mount, the Pentax/Samsung K-mount and the M42 screw mount.

The 100mm ƒ/2 is a full-frame lens, built to ''old-school'' specifications that guarantee compatibility with older camera bodies. On a sub-frame digital sensor body, the lens will have an effective field of view of 150mm. The lens takes 67mm filters, and comes with a bowl-style metal lens hood.

Sharpness
This is a very sharp lens.

The Zeiss 100mm ƒ/2 produces very sharp results when shot even wide open at ƒ/2, but achieves tack-sharp results when stopped down to ƒ/4. This is true whether shooting sub- or full-frame.

Images shot at ƒ/2 render approximately 1.5 blur units across the frame, and by ƒ/4 this performance hits its peak at just 1 blur unit. Performance is imperceptibly better at ƒ/5.6, and only starts to degrade by ƒ/16 with the introduction of some minor diffraction limiting. Degradation is almost insignificant, as it's only by ƒ/22 that we see 1.5 blur units again. This performance is identical between sub- and full-frame camera bodies.

In short, excellent performance.

Chromatic Aberration
Resistance to chromatic aberration is very impressive. Image performance seems to be optimized for wide-open shooting. On a sub-frame sensor body, CA is almost non-existent when images are shot at ƒ/2. CA increases very slightly at other apertures, but never exceeds 2/100ths of a percent of frame height in the corners, and half that on average. In short; you will have a very hard time picking out chromatic aberration.

On a full-frame sensor body, CA performance is essentially identical to the above; extraordinary. We have produced two charts for our full-frame results, as our full-frame test body, the Nikon D3, has automatic chromatic aberration removal. As can be seen in comparing those two graphs, there's not much chromatic aberration to remove.

Shading (''Vignetting'')
The Zeiss 100mm ƒ/2 has slight issues with corner shading, but only when shot wide open at its largest aperture, ƒ/2. Specifically, on a sub-frame camera body, images will show up as a half-stop darker in the corners than in the center. On a full frame camera body, this corner shading is slightly more prominent at 2/3 of a stop. In either case, light falloff ceases to be an issue with an aperture set to ƒ/2.8 or smaller.

Distortion
The Zeiss 100mm ƒ/2 produces statistically insignificant results for distortion; essentially, this lens produces distortion-free results.

Autofocus Operation
The Zeiss 100mm ƒ/2 is a manual focus lens.

Macro
Macro purists may object to the fact that the image reproduction ratio for this lens is in fact only 1:2 (0.5x); images are not reproduced as ''life-size'' on the sensor. However, it performs very well in this capacity, with a minimum close-focusing distance of 44 cm (just over 17 inches). This is from the image plane, so taking into account the length of the lens, this means you can be as little as 9 1/4'' away from your subjects. The width of the subject area at closest focus is 45mm on a sub-frame sensor body, and 72mm on full-frame sensor body.

Build Quality and Handling
Carl Zeiss seems to have taken a retro approach with its line of ZF lenses, in that instead of adopting a new design approach they are solidly capitalizing on a proven concept of an old design. The sample we tested is built with the old Nikon ''rabbit-ears'' AI indexer, to ensure compatibility with some of the oldest Nikon bodies produced.

The lens is a simpler design, with 9 elements in 8 groups and a nine-bladed diaphragm making up the aperture. The production quality of the lens is superb; the entire construction is metal, from lens mount to filter rings. Accordingly, this makes it rather heavy at 680g (1 1/2 lbs). As a macro lens however, I don't see this as much of a problem as your average macro shooter uses a tripod to ensure the absence of camera shake. Unless your newer camera body supports AI- or AIS-style lenses, you can forget about ''advanced'' modes such as aperture priority; it will be manual mode all the way. And you can forget about metering, as well. My sense is that the average purchaser of this lens will not have such problems.

Those issues aside, the lens is wonderfully presented, with a distance and magnification scale etched into the focus ring. A depth-of-field scale (complete with infrared index) is adjacent to the aperture ring. The aperture ring itself clicks between ƒ/2 and ƒ/22 in half-stop intervals. A 2-inch deep metal bayonet-style lens hood completes the ensemble. The lens hood can be reversed for storage on the lens.

The focus ring is the main operating feature of the lens, at 5/8 of an inch wide, with a ribbed metal texture. There is plenty of travel on the smoothly-cammed ring - almost a complete 360-degree turn brings you from closest focus to infinity.

Alternatives

Pentax 100mm ƒ/2.8 Macro SMC P-FA ~$500
The Pentax 100mm macro lens achieves true 1:1 magnification with a closer minimum focusing distance. It also has much more advanced focus control options, such as a stiffness clamp to be very selective about how focus is achieved. That said it's not as sharp as the Zeiss, only achieving the same tack-sharp results by ƒ/5.6. CA performance isn't as good.

Nikon 105mm ƒ/2.8G IF-ED AF-S VR Micro Nikkor ~$900
The advantage of the Nikon 105mm macro lens is its built-in vibration reduction, reducing the need for a tripod; however, it's actually slightly heavier than the Zeiss 100mm. It's also not as sharp, with the Nikon never achieving the same tack-sharp quality of the Zeiss 100mm. The Nikon achieves true 1:1 magnification and has a closer minimum focus.

Sigma 105mm ƒ/2.8 EX DG Macro ~$400
Available for all camera mounts including the 4/3 sensor, the Sigma 105mm macro lens achieves true 1:1 magnification, focuses closer, and is much lighter than the Zeiss 100mm. However, it isn't as sharp, only achieving tack-sharp results by ƒ/8. CA, distortion and corner shading results are very good.

Tamron 90mm ƒ/2.8 Di Macro 1:1 SP AF ~$450
Available in all camera mounts but four-thirds, the Tamron 90mm macro lens is much lighter than the Zeiss, offering true 1:1 macro reproduction with a closer minimum focusing distance. It's not as sharp as the Zeiss, achieving tack-sharp results by ƒ/5.6. CA performance isn't as good, while distortion and corner shading results are good.

Tokina 100mm ƒ/2.8 AT-X 100 AF PRO D ~$350
Tokina offers a 100mm macro lens in Canon, Nikon and Sony mounts. It is lighter and focuses closer than the Zeiss, offering true 1:1 magnification. We haven't tested it, so we can't comment on its image quality.

Conclusion
As you can see from the above alternatives, there are plenty of lenses to choose from in the 100mm macro category for both Nikon and Pentax users. The Zeiss 100mm ƒ/2 has much to commend it: it's a full stop faster than its contemporaries, and its results for sharpness, chromatic aberration, corner shading and distortion are all exceptional. It's also built extremely well, with a construction finish that will last dozens of years and bear up well under harsh conditions.

That said, there are a two sticking points for this lens. The first issue is the lack of autofocus capability. While not essential, autofocus is very important when using a sub-frame camera body; there simply isn't as much real estate as a full-frame camera body in the viewfinder, to accurately judge focus. As well, most modern SLRs lack useful focusing features such as a split-prism focusing screen to assist in accurate manual focusing. The second issue is the fact that its reproduction ratio is only 1:2. If you shoot macro, this point alone could be a make-or-break issue for you. But if neither of these points ranks with any significance for you, and if you have a spare $1,500 kicking around and a need for the sharpest macro performance money can buy, then the Zeiss 100mm ƒ/2 is probably in your future.

Sample Photos

The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.

Still Life shot

VFA target

As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.