Carl Zeiss Planar T* 50mm f/1.4 Carl Zeiss Planar T* 50mm f/1.4

 

Introduction

Carl Zeiss Planar is one of the oldest optical designs in the company's lineup, first invented by Dr. Paul Rudolph 1896. The original Planar had a simple (by modern standards) symmetrical Double-Gauss design, and while the design saw some tweaks over the years, the overall concept remained pretty much the same. And why not? Simple is often beatiful and the popularity of Planars over the years has proven this case. The 50mm Planars were continuously manufactured by Carl Zeiss in various camera mounts since early 1900s. The Contax/Yashica version of the lens, which is reviewed here, has been manufactured from 1974, when Carl Zeiss officially announced partnership with Yashica of Japan to manufacture its new RTS system, to 2005 when Kyocera (which acquired Yashica in 80s) exited the camera business. Unfortunately for Carl Zeiss, at the moment of its exit from camera market, Kyocera still held a licensing on Contax brand. Unfortunately because this has put restrictions on Carl Zeiss being able to use this legendary brand name with its new products. But good things come to those who wait - the licensing agreement with Kyocera expired in 2008, so we can probably expect Contax branded products appearing on the market pretty soon.

Back to the Planar T* 50mm f/1.4. Like its slower f/1.7 cousin, Carl Zeiss Planar 50mm f/1.4 for Contax/Yashica mount was manufactured in AE and MM formats. Both variants are pretty common on the used markets these days, with good quality copies fetching ~US$250. Carl Zeiss recently resurrecrted the 50mm Planar by introducing this lens in 4 new mounts - Nikon F (ZF), M42 universal screw (ZS), Pentax K (ZK) and even Canon EF (ZE). The new version of the lens sells anywhere from ~US$550 to ~US$65, depending on the mount.

The lens is a classical manual focus prime and sports dedicated aperture and focus rings. The build quality of the lens is superb, with a metal barrel and fully rubberized focus/aperture rings. The focusing ring is pretty smooth to operate and the aperture is snappy, snapping into positions with a satisfying click. The optical construction of the lens consists of 7 elements in 6 groups - a pretty timeless design. The lens is pretty compact, measuring only 6.3 x 4.1cm (2.4 x 1.6in), although the barrel of the lens extends slightly during focusing towards the closeup. The lens weighs a mere 275g (9.7oz). The minimum focusing distance is 45cm (1.5ft) and the minimum supported aperture is f/16 (the aperture ring moves in one full f-stop increments). The lens accepts 55mm screw-in filters.

Image

To test the lens on Canon EOS body, I used a generic Contax/Yashica to EOS adapter without AF confirmation. Like with any other non EF (or EF-S) mount lenses, you will have to operate your SLR camera in aperture priority or fully manual mode. You will also loose all but center weighted metering unless you use a  specially chipped adapter. On APS-C type cameras with 1.6x crop ratio like Digital Rebel XTi used here for testing, Zeiss Planar 50mm f/1.4 has a field of view equivalent to that of an 80mm lens on a full-frame body.

 

Summary
Lens Composition 7 elements in 6 groups
Angular Field 45 degrees
Minimum Focus 45cm/1.5ft
Focusing Action MF
f-stop Scale f/1.4-f/16, manual
Filter Size 55mm
Lens Hood G-11 soft or No.4 metal hoods (optional)
Weight 275g/9.7lbs
Dimensions 62.5x41mm/2.4x1.6"
Lens Case No.1 (included)

 

Field Tests

With the advent of alternative lenses on Canon and other digital SLR cameras, old Contax primes and to a lesser degree zooms have suddenly saw a resurgence in popularity. And why not - for a fraction of a price of a modern lens you get an often as good if not better quality optics from a renown manufacturer. Of course as the popularity of the old Contax lenses increased so did the prices, to the point that in some cases used lenses now cost more then their Canon, Nikon or whatever equivalents. Carl Zeiss Planar T* 50mm f/1.4 has seen such an increase in popularity - it is as if scores of photographers suddenly decided to give up on all those modern capabilities such as auto-focusing, in favor of a (often argued about) image quality. The arguments floating on many photography forums are quite intense. Is MM version of the lens better then AE verions (there should be no difference in theory since both versions have same optical formula and the only difference is in the diaphragm construction)? Are the lenses made in Germany better then those made in Japan (again, in theory they should be equivalent, since the lenses made in Japan carried exact same design as those made in Germany)? And so on, and so forth...

First thing first however. If you are planning on using Contax Carl Zeiss Planar 50mm f/1.4 on your Canon 5D, be forewarned that MM versions of the lens do not clear the camera's mirror, causing it to lockup during shooting. There is no universal opinion even about this issue and it looks like there is some variance in the construction of Canon 5D's mirror box that sometimes causes this issue. Another possible explanation is the thickness of your Contax to EOS adapter since there does seem to be a pretty wide variance in the thickness of adapters currently being sold all over the Internet. One way or the other, you should certainly be careful so you don't damage your camera - two different copies of MM lenses tried in this test did lock up the mirror. On the other hand, AE versions of 50mm Planar f/1.4 don't seem to have this problem in general - at least there have been no reports about mirror lockup with AE versions of this lens, plus four different AE samples tested  here (including an anniversary edition sample) worked just fine. And if you are using a Canon APS-C or APS-H camera or one of the 1Ds series of full frame cameras, or even a Four Thirds camera, then both MM as well AE versions of the lens should work just fine for you.

But enough on compatibility. Contax Planar T* 50mm f/1.4 is a tiny lens by all standards and some might find it somewhat hard to operate - the focus ring is broad enough to grasp comfortably, but the aperture ring is way too close to the camera body and thin enough to make it somewhat hard to grasp. Why is this a problem? After all, you  can preset the aperture and then focus the lens normally or even use an engraved DOF scale for hyperfocal distance for focusing. Well, Planar has absolutely no coupling with your lens, so when you stop down the aperture, the diaphragm actually closes down. This in turn darkens your viewfinder. Manual focusing through viewfinder with no visual aids like split circle screen by itself is not the easiest task and with the lens stopped down to about f/5.6 the viewfinder gets so dark that focusing the lens accurately becomes practically impossible.

Overall image quality that the lens showcased in the field was pretty good. From about f/4 the lens showed pretty consistent results on both APS-C as well as FF cameras throughout the picture frame, that is there did not seem to be any significant difference in image quality from the center to the borders. The widest aperture setting is where the image quality was noticeably different across the image frame, with border quality noticeably worse then in the center. One can argue that softer borders at the widest aperture settings is not much of a problem since you would want to have a smooth bokeh with a better separation between the subject in focus and out of focus areas.

 

ISO 400, 1/250, f/1.4, 50mm (Canon 5D)
ISO 400, 1/250, f/1.4, 50mm (Canon 5D)

Speaking of the bokeh. From the sample picture above as well as pictures in the sample gallery, you can notice that when shot with wide open aperture, Carl Zeiss Planar T* 50mm f/1.4 produces occasional harshly lit edges around out of focus highlights, although the OOF highlights themselves are pretty uniformly lit. Other then that though, the lens showed pretty decent characteristics, including smooth transitions in the fore/background and lack of any double-edging around out of focus objects, all of which should make the look and feel of bokeh quite pleasing.

On APS-C type cameras with 1.6x crop sensor the lens showed very minimal vignetting at wider apertures, but the lens did not fare as well on a full-frame body, where it showed noticeable vignetting at f/1.4, which was reduced at f/2 and became almost non-existent at f/4. Color rendition was quite good, but the resulting images were somewhat 'cooler' compared to similar lenses from Canon and Sigma. The lens did not exhibit any barrel distortion. Color fringing was very minimal across the frame. The lens also showed minimal amount of flare with wide open aperture.

 

Vignetting @ f/1.4 - full frame vs 1.6x crop
Vignetting @ f/1.4 - full frame vs 1.6x crop

 

As with other manual lenses, focusing with Carl Zeiss Planar T* 50mm f/1.4 is somewhat of a hassle unless you use an adapter with AF confirmation or your camera has a built-in rangefinder. The experience is even worse on entry level cameras like Digital Rebel XTi, which have smaller and darker viewfinders - an AF adapter is practically a must with such cameras. Alternatively, you can replace your standard focusing screen with one specifically designed for manual focusing. In Canon's case this is either EE-S or a custom cut screen from one of the third party vendors like Katz Eye.

 

ISO 100, 1/4000, f/1.4, 50mm
ISO 100, 1/4000, f/1.4, 50mm

 

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: One would expect that both C/Y mount variations of Zeiss' 50mm Planar would exhibit similar performance characteristics. Yet the results were somewhat surprising - the f/1.4 version of Planar clearly lagged behind the slower f/1.7 lens, most notably in sharpness around borders. But I'm rushing ahead... Zeiss Planar f/1.4 showed very good overall performance. At f/1.4, the lens is pretty sharp in the center and performance gets only better as you stop down. Border quality is different story however. The lens is pretty soft around borders at f/1.4. It gets slightly better at f/2, but does not really impress here either. Only starting at f/2.8 the 'Zeiss power' kicks in and starts delivering outstanding border performance. Not surprisingly, the lens shows the top notch overall performance from f/2.8 through f/8, where you would be able to obtain outstanding 16in and very good 19in prints. Overall, from f/2.8 to f/8, the lens can go neck to neck with the super heavyweights of the industry like Canon EF 50mm f/1.2L, but, and here's the kick - the slower and cheaper f/1.7 version of Planar actually outperforms the faster and more expensive f/1.4 version from f/4 through f/11 BOTH around the borders and in the center. Go figure... (well, actually I'm not totally surprised, since by now I have already seen a few other, 'cheaper' variations of various lenses, delivering as good and sometimes even better results then their more expensive brethren). Conclusion? Excellent 50mm prime, with one weakness - border quality at f/1.4. It remains to be seen if Carl Zeiss improved overall performance in their latest variation of the lens released in Nikon, M42 and Zeiss M mounts.

 

MTF50 (Line Width/Inch on the Print) @ 50mm
MTF50 (Line Width/Inch on the Print) @ 50mm

 

Normalized raw MTF50 @ 50mm
Normalized raw MTF50 @ 50mm

 

CA? What CA? Chromatic aberration is already negligible at f/1.4 and becomes non-existent once you stop down to f/2.8. Truth be told, after working with and testing about half a dozen different Contax branded lenses (from ultra-wide all the way to medium telephoto) I have yet to see a Zeiss lens that shows any major chromatic aberration. As I have been saying in other reviews, this is the signature aspect of Zeiss' lens designs.

 

Here are 100% crops, taken with an APS-C type Canon Digital Rebel XTi, comparing image crops at f/1.4 and f/8.

 

Image borders @ 50mm (100% crop): f/1.4 vs f/8
Image borders @ 50mm (100% crop): f/1.4 vs f/8

 

Canon FF: Performance trend of the lens on the full-frame body resembled that on an APS-C camera. Center performance is rather average at f/1.4 but quickly improves once stopped down and by f/2.8 reaches very respectable level (and stays at the high level throughout the rest of the tested aperture range). The border quality also suffers at wide aperture settings and in the f/1.4-f/2 range is pretty unimpressive. Quality improves drastically at f/2.8  and remains on a high level through f/11. Conclusion? The lens performs consistently well on both APS-C and full-frame cameras - f/1.4 though remains a weak point.

 

Normalized raw MTF50 @ 50mm
Normalized raw MTF50 @ 50mm

 

Distortion was quite minimal, which is not that much surprising for a 50mm focal length. The lens showed 0.61% barrel distortion, which should not really affect general type photography.

 

Distortion (FF) @ 50mm
Distortion (FF) @ 50mm

Like with the APS-C camera, chromatic aberration on a full-frame body was pretty minimal with the widest aperture setting. CA was averaging less then 0.5px in the center and ~1px around borders. Once stopped down to f/2.8, CA pretty much disappears.

 

Here are 100% crops, taken with a full frame Canon 5D, comparing image crops at f/1.4 and f/8.

 

Image borders @ 50mm (100% crop): f/1.4 vs f/8
Image borders @ 50mm (100% crop): f/1.4 vs f/8

 

Alternatives

As mentioned earlier, there are quite a number of variations of the original Zeiss Planar lens available out there. Carl Zeiss currently manufactures Planar T* 50mm f/1.4 for a number of mounts, including Nikon (ZF), M42 (ZS), Pentax K (ZK) and Canon EF (ZE). The older versions include the slightly slower variant Contax Carl Zeiss Planar T* 50mm f/1.7 as well as its predecessor Carl Zeiss Planar HFT 50mm f/1.8 for Rollei mount. However, if you're really into alternative lenses, you might expand your search to include Leica's Summilux-R 50mm f/1.4 and Summicron-R 50mm f/2 as well as old Asahi Pentax SMC Takumar 50mm f/1.2or its slower version SMC Takumar f/1.4. For a side by side comparison of a number of 50mm primes, you might also take a look at the 50mm Challenge.

 

Recommendation

Contax Carl Zeiss Planar T* 50mm f/1.4 is clearly one of the better 50mm lenses available on the market. As with other manual lenses, the major weakness of the lens is, well, the fact that it's a manual lens... It's certainly not the fastest 50mm lens on the market - that title belongs to Leica's Noctilux 50mm f/1 and now discontinued Canon EF 50mm f/1, but for practical reasons f/1.4 is fast enough for the majority of photographers out there. The lens clearly shows some weakness, specifically the image quality at wider apertures. Still, if you are looking for a 50mm prime and are not concerned about the largest apertures, then you should seriously consider Planar's slower fariation, the venerable Planar T* 50mm f/1.7- you will be able to save some dough without sacrificing any performance. If you do require a fast aperture like f/1.4, then makre sure to compare image quality of Zeiss Planar 50mm f/1.4 and a number of other 50mm primes such as Canon EF 50mm f/1.4 and Leica's Summilux 50mm f/1.4. If you already own the lens - congratulations, it's a keeper!