Carl Zeiss Planar is one of the oldest lens designs currently still in active production. The first design dates back to 1896 and since then the lens has gone through numerous design revisions. Zeiss is currently manufacturing Planar for several camera mounts, including Nikon, Hasselblad and Zeiss Ikon. The lens reviewed here is one of the newer MM-type designs manufactured by Tomioka Optical, a division of Yashica/Kyocera. The serial number of the lens is 8405886.
Planar 50mm f/1.7 is a classical manual focus Zeiss lens consisting of 7 elements in 6 groups. The build quality of the lens is quite good - the lens barrel is built of lightweight metal and both focus and aperture rings are fully rubberized (and smooth despite the age of the lens). The lens is very light and compact - almost miniature, measuring 6.1x3.6cm (2.4x1.4in) and weighing only 190gr (6.72oz). The lens extends slightly when focusing towards close-up, but the front glass element does not rotate, so you will be able to attach a circular polarizer to the front thread. The filter size if 55mm. The minimum focusing distance for this lens is 60cm (2ft) and the minimum supported aperture is f/16. On an APS-C type cameras with 1.6x crop ratio, the field of view of the lens is similar to that of an 80mm lens on a full-frame body.
To test the lens on Canon EOS body, I used a generic Fotodiox Contax/Yashica to EOS adapter without AF confirmation. After attaching the lens to my Rebel XTi I had to operate the camera in aperture priority or full manual mode without any AF (if you do plan to use the lens extensively on non-native mount, do yourself a favor and buy an adapter with AF confirmation). Also keep in mind that you would loose all but center metering mode when using this lens on Canon body.
Used copies of Planar are quite affordable - you can find a really good copy on eBay or specialty retailers for about $150-$200. A new copy would cost you a whopping $640 at retailers like B&H - still affordable if you compare it to say Canon EF 50mm f/1.2L
|Lens Composition||7 elements in 6 groups|
|Angular Field||45 degrees|
|stop Scale||f/1.7-f/16, manual|
|Lens Hood||G-11 soft or No.4 metal hoods (optional)
|Lens Case||No.1 (optional)|
The lens was flawless. Sharp throughout the aperture range it performed exceptionally well from f/2.8. At f/1.7 it produced very nice bookeh. Image quality in the center as well as around borders was excellent - rivaling all other, including Canon's L, lenses I tested to date.
My only gripe, and this is a general gripe not necessarily about this particular lens, is that it's so much harder to use manual focus lenses on modern digital SLRs. Back in 70s and 80s we used to have microprism and split-screen ground focusing that helped focus better with manual lenses, but most manufacturers abandoned these in favor of fully automated focusing systems. And while AF is a great invention and is very useful in a wide range of situations, I feel that we all lost something here (unless you enjoy squinting while trying to focus your favorite manual lens).
Bokeh handling was somewhat of a mixed bag. OOF highlights carried bright, well-defined edges, which hints on over-corrected spherical aberration. Contrast transitions in background OOF areas were more or less smooth and there was no double-edging around OOF objects.
The lens produced mild level of vignetting at f/1.7 with a full-frame camera and none whatsoever with an APS-C body. The lens help up well against flare and distortion, but did produce minor color fringing as could be seen from the crop below.
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: Carl Zeiss Planar T* 50mm f/1.7 performed exceptionally well in the lab. The lens was sharp throughout the aperture range - both center and border image quality remained especially high in the f/2.8 to f/8 range, where you would be able to get outstanding 19in prints. Border quality suffered to some extent with wide open aperture - f/1.7 was the weakest point, but weakest is a relative term here, since what was weak for Zeiss Planar is often best performance for some other lenses. Conclusion? Impressive results indeed. I'm waiting for the day when Zeiss announces support for Canon's EF mount (if you're a Nikon user then that day has already arrived since Zeiss is now producing ZF series of lenses for your beloved dSLRs).
As expected from a standard prime lens, chromatic aberration was very well under control and I would even say non-existent throughout the aperture range (well, technically speaking CA was less then 0.2px, which I still consider to be negligible).
Canon FF: The lens produced quite impressive results with a full-frame body as well. Performance in the center was top notch straight from f/1.7 through f/11. Border quality is somewhat weaker with wide open aperture - at f/1.7 and f/2 performance is decent but not impressive. Once stopped down to f/2.8 (and throughout the rest of the tested aperture range), the lens shows outstanding border quality that closely matches performance in the center. Conclusion? While the lens does suffer somewhat around borders at wide aperture settings with both APS-C and FF cameras, overall quality is still one of the best among 50mm prime lenses.
Amount of chromatic aberration with a full-frame camera remained pretty much negligible and did not exceed ~0.3px around borders at the widest aperture setting.
When considering alternatives, I'm going to assume that you're primarily interested in other non-native mount lenses. The first lens that comes to mind is Planar's other variant, the f/1.4 variation of the lens. If you're willing to look outside of Zeiss camp, then Leica has two potential options here: the Summilux 50mm f/1.4 (review) and the Summicron 50mm f/2. Another potential option is Voigtlander Ultron Aspherical 40mm f/2 or Voigtlander Topcor 58mm f/1.4 (both lenses are available in Nikon Ai-S mount)
The overall performance of the lens is quite enviable, even when measured by today's standards. If you're using a Contaxt/Yashica mount camera, then the recommendation is very simple - get the lens! If you're trying to use this lens on a non-native mount (i.e. Canon - there's no reason to use this particular lens on Nikon since Zeiss manufactures Planar for Nikon Ai-S mount), then the answer gets a bit tricky. The lens goes head to head with some of the best 50mm prime lenses manufactured by Canon, Nikon, Sigma and others, but it is a fully manual lens. If you're comfortable with that fact then the lens can be a great addition to your collection - results will not disappoint you. Otherwise, stick to the basics and go with one of the OEM lenses.