PHOTOOG Photography writings by Olivier Giroux


Carl Zeiss 2/50 Planar T* Review


The 50mm Planar ZM is one of the simplest lenses ever made, yet performs more robustly and consistently than almost any other lens. It is very closely related to the more-storied 50mm Summicron-M, of nearly identical size and capabilities, that it challenges in the marketplace. This Planar is a fundamentally boring lens with its lack of buzzwords to rave about and also substantive flaws to gripe about.

In my review of the 1.4/50mm Planar ZF I emphasized the direct connection between that lens and the “double gauss” optical layout from the 19th century. In actuality the design of the ZM lens is even more closely related to this precursor, resembling more closely that of pre-WW-II designs than any other modern lens. Adding T* coatings to a lens design originally devised to maximize contrast without the use of coatings has produced a lens with phenomenal contrast and resistance to contra-light.

This is my third 50mm lens, and fourth 50mm lens review. Despite appearances this focal length is not my favorite but I admit that it is very versatile and an excellent teacher. As I experience it the M system pushes the photographer towards using 50mm more than other systems, in part because of the default choice of magnification in the viewfinder.


The 2/50mm ZM is in most ways operationally the same as the 2/35mm ZM. The two lenses share the same lens barrel, down to the last detail. For the overall description I will refer you to that review.

One small difference between the two lenses is the amount depth of field they provide, obviously with the Planar providing less of it. It hasn’t been an issue for me however because 50mm at f/2 still provides plenty of depth of field to hide small errors at most focus distances.

Besides this there is an annoying detail common to both the Biogon and the Planar, but much more so on the Planar, where the first glass element is fixed to the lens’ faceplate. A double-threaded ring is screwed here on top of the first element, with two diametrically opposed notches that I presume to serve in the assembly process. These notches have sharp corners that frequently catch threads in microfiber cleaning cloths, getting in the way of a smooth cleaning and sometimes damaging the cloths. This is rather sloppy and unusual for Zeiss.

The 0.7m close focus limit is absolutely not an issue with this lens, much as it has been for me with some other lenses in the M system. Likewise for focus shift. Like the Biogon lens this Planar is not corrected for close focus as it lacks floating elements.


The 50mm Planar ZM is not the strongest-performing lens there is at f/2, but it just might be after f/4. It also doesn’t have any major flaws at any aperture.

At the full aperture of f/2 the Planar draws with high resolution and high contrast on-axis, and good contrast over the majority of the frame. Fine detail is resolved all the way to the borders in fact, but contrast is lower there because of halation artifacts – probably due to residual spherical aberration. Although fine detail can be seen at the image corners, the micro-contrast there is extremely poor.

One stop down from the full aperture, at f/2.8, contrast and resolution in the image center improve to extremely high levels. Likewise the outer image regions now attain levels similar to what the image center delivered at f/2, but the corners still come out a bit short of useful. Halation is greatly reduced along extreme contrast edges at this aperture.

At all of the smaller apertures, from f/4 onwards and until the diffraction limit, the Planar’s performance is outstanding: extreme contrast and resolving power over the entire frame. This performance stretches to the image corners now, and even there aren’t any halation artifacts. At these apertures you will definitely encounter some moiré on the M9 camera, no matter the subject matter. Contrast is slightly lower at f/8 than it is at larger apertures.

Performance at close range is less than stated above, and degradation is perceptible when working at a couple of meters or less. Even down to the 0.7m close focus limit performance is still quite good though, and is rarely the limiting factor when you consider how poor indoor lighting typically is. Only a few 50mm lenses are available that correct for this effect, most notably the Summilux-M ASPH.

The Planar is very resistant to veiling glare when used in contra-light, particularly if you can afford to stop it down once or twice. Flares spots can be produced under the right conditions, as with any lens, though you will get large blooming patches more often than spots.

Bokeh is understated and simply excellent, with no distracting artifacts. Zones of defocus are simply blurred as if by a perfect Gaussian filter in Photoshop. The transition from focus to defocus is plain – neither abrupt nor the elongated type found in the best portrait lenses.


The 50mm Planar ZM is a very good lens, there isn't much else to say.  It's unlikely that either the Summicron-M or Summarit-M lenses perform much better than this lens on the M9 camera.  Its excellent performance on-axis at any aperture suggests to me that it is also an excellent choice of short telephoto lens for cropped-frame mirrorless cameras.

Would I recommend this lens to other photographers? Yes.



Comments (16) Trackbacks (0)
  1. “The 50mm Planar ZM is not the strongest-performing lens there is at f/2, but it just might be after f/4”

    It needs to be said, that every 50mm available today, or in the last 30 years, is fine after f/4. The lenses today need to perform great wide open, but if not (like the awful ZF 50/1.4), they’re not worth buying.

    Unfortunately, the only great 50mm lens today is the Leica 50/1.4 M ASPH. Others are either poor, or good but slow (50/2 ZF Makro-Planar).

    • I have yet to test a lens that is really great wide-open, and I have yet to test the 50mm Summilux ASPH.

      I don’t subscribe to most of your argument, irrespective. Even if that lens is as great in real life as on paper, it still doesn’t completely overcome the issue of its huge cost.

      • Of course, no Leica lens can ever overcome the issue of what they cost. But if you do get the chance to try the 50/1.4 M ASPH, I bet you’ll be impressed, I find the bokeh especially impressive.

    • There is Another: the terminal Summilux-R (1998). As good as the -M? Likely not. But in practical terms, it was *darned* good, and certainly better than any other fast 50 made for SLRs, before or since.

      • I know of that lens, but the bokeh is not very appealing to me. I dont know what it is about 50mm lenses, most of them do not have appealing bokeh at all. Among the 50mm lenses you have:

        great bokeh (50/1.4 M ASPH)
        mediocre at best (Sigma 50/1.4, Canon 50/1.2, Zeiss 50/2 ZF)
        ugly (all Nikkors, Zeiss 50/1.4, Canon 50/1.4)
        and the weird (early Summilux-R)

        Really, I’ve looked far and wide, and havent found one lens that compares to the 50/1.4 M ASPH. Unfortunately so, because the price of that lens is hard to swallow. I’m dying for someone to make a modern 50/1.4 that will kick ass and will not cost 4,000 dollars, like the Leica.

        • Good luck with that. E. Puts claims the glass in ONE special element in the -M ASPH costs as much as ALL elements in the previous version Summilux.

        • …and, I’ll add: if you’re that freaked out about bokeh, the best way to optimize it is through expert use of the lens. Almost any lens can give beautiful or ugly backgrounds; the deciding factor is the skill of the artist more than the designer of the optic.

        • I will point out that the Bokeh out of the Planar reviewed in this article is quite good! I know it doesn’t compete resolution-wise with the Summilux until about f/2.8 but if what you want most is good Bokeh then it does deliver that quite consistently.

  2. I find it a bit blase to boldly state that there is only one 50mm lens with a sufficient good bokeh. That lens costing €2600. We are talking a €700,= lens here! I would be very disappointed if the Lux 50 would not be much, much better! As compared to all other lenses in the world I think the Planar is almost the best in its class. According to Erwin Puts its quality is equal to the Cron 50 that is costing twice as much.

    As for the ZF 50/2.0 Planar: I posess that lens and I find its bokeh almost as good as the Planar 100/2.0 that I also own and that is rated as one of the best bokeh in the world. And this lens too is costing much less then comparable Leica lenses.

    In absolute quality the Leica lenses will definitely be better then the CZ’s. In practical, day to day work I think the quality difference is neglible and only the appearance of the pictures is visible.

  3. if bokeh is ur thing, u might wanna give the ZM 50/1.5 a shot. not sure if it’s as good as the Leica, but it has received a lot of praise for its bokeh.

  4. Bokeh is definitely MY thing. At 35mm, the Summarit-M has outstanding bokeh. I just bought the 50mm ZM Planar after seeing many samples of its bokeh, and have Summarit-M 75mm and 90mm as well.

    But when I really want to go nuts with bokeh I always reach for my 1963 Russian Jupiter 3, which has the same optical formula (nowhere near the build-quality) of the ZM Sonnar. My J3 was tuned for use on the Leica M by a true expert in Sonar lenses, and has been optimized for close focus wide-open at f/1.5. It gives the same “Sonar Look” as the $1200 ZM 50/1.5 Sonar, though admittedly it is quite prone to flare.

    • WOW,

      Haven’t read this in a long time.

      To address a few things. The only reason the 100 MP has “one of the best bokeh signatures of all time” is mainly due to the fact that people rate it at close distances. Most macro lenses have good bokeh close up.

      I recently purchased the 50 Noctilux and I find it’s very contrasty in the bokeh dept, but naturally at .95 and 1m it gives “good” bokeh. I also purchased the 50APO and that’s probably now my favorite lens. But the bokeh still isn’t fantastic.

      And someone else mentioned that you can get good bokeh from any lens. That’s simply not always feasible. Repositioning yourself, or finding a less distracting background is fine and dandy when shooting a model/friends etc. When shooting a wedding, photojournalism, street etc.. It’s not possible to make a bad lens look good all the time, just because you “know how to use it”. That and lens to subject to background distance plays a large part, but if I want to use the 50mm to get a half body shot, and the only good bokeh is at headshot distances, then my lens is now dictating how I should shoot, and that’s ridiculous.

      Lastly, bokeh is subjective, and there’s always going to be a give and take. There are times (many) when my 50Lux-asph doesn’t give me good bokeh. But on a whole, it’s the most pleasing ratio of good bokeh to subject sharpness that I’ve gotten in a 50mm lens. And signature that I like.

      If you don’t consider sharpenss, then I’d say the 55mm Contax 1.2 has everything beat at close focusing distances. And the new Otus is looking like a champ from headshots to half body, although at full body distances, I’m seeing things I don’t like.

      These are all just opinions, so no real need to get to worked up. And yeah after using the 50/2 ZM more and more, I’ve come to the conclusion that for sub $1k, it’s really very close in performance to the $8k 50APO, aside from the look/feel/mood/signature (whatever you want to call it). In fact, it does way better with veiling flare, and flare in general.. But lacks the sharpness wide open, and the smooth leica-typical contrast. Bokeh is a bit more hazy with the 50APO, which I like as well. But all in all a good alternative to the user who doesn’t want to spend so much.

      Although now with the A7 and 55 1.8, it’s a no brainer if you have $2500-ish to spend on a setup.

      • Hrm, well I don’t entirely agree. Mostly I disagree with some details you mention, because in general I think you’re right about the finicky nature of bokeh and the management thereof. I don’t think I’m guilty of the crime of confusing the amount of blur and its quality, or biasing my field experience of the 100MP to close ups only, or even mostly.

        I would love to spend time with a 50APO.

      • I would argue that every lens dictates how you shoot, regardless of quality.

        As for quality of Bokeh, well it’s all subjective and I’m not sure why people obsess so much about it. Generally I don’t compose my images in such a way that the viewer’s eye is attracted to things that are out of focus, so as long as it’s not outright distracting, I’m not overly concerned about it. Besides, a shorter lens like a 50mm will never give as pleasing a bokeh as a longer lens.

  5. As an enthusiast on a budget, this review of the Zeiss 2/50 Planar does it for me. I’ve read reviews of the Planar ZM from several trusted sites. I find your comments and samples of its bokeh, which are lacking or glossed over in the other reviews, very helpful indeed.

    Bokeh is not on top of my check list. Otherwise, I would have opted for the 1.5/50 C Sonnar. For my first 50mm lens, I want a “boring lens with no issues” for use as “daily-driver”. The other candidates in my wish list were: the Nokton 50/1.5 VM, M-Rokkor 40//2, and a boxed Summicron 50mm (3rd gen) in mint condition (my first choice but somebody beat me to it!). Of the lenses I own, the Pentax M42 Tele-Takumar 200/5.6 preset makes the best bokeh, better than that of my Heliar Classic 75/1.8 VM. But bokeh counts only if the subject is in critical focus. (I use my M lenses on my Ricoh GXR-M. The M42 Takumars are adapted with a vintage Novoflex Leico M42-M39 “step-down” ring and a LTM-LM adapter, a precise and unobtrusive combo.)

    So I’m off to Hong Kong in a few days to buy my first 50mm. The Planar is it.

    Thanks, Olivier!

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