Zeiss 50mm F/1.5 Sonnar versus F/2 Planar – a Film Shooter’s Opinion

Zeiss 50mm F/1.5 Sonnar versus F/2 Planar – a Film Shooter’s Opinion

2000 1125 Dustin Vaughn-Luma

When it comes to M mount 50mm lenses the choices are plentiful, and quite often the costs are high. Single coat, multi coat, ‘crons, ‘nars – the overwhelming abundance of choice is enough to send even the most seasoned shooters into a chronic case of GAS, or running for another system. Fortunately, Uncle Carl (who was most likely a practical man) has two outstanding offerings that I was fortunate enough to spend the past few weeks shooting courtesy of our friends at B&H – the C Sonnar T* 1,5/50 ZM and the Planar T* 2/50 ZM.

My intention here is to compare these lenses and decide which one I’d choose. This is not a complete technical review of either lens. For full specs and DxO marks, there are other sites. This is a practical approach. The image samples that follow were shot on a few of my favorite film stocks, and as such, I’ll speak to the results through that lens (pun intended). If you’re after digital image samples and pixel scrutiny, browse around elsewhere after reading this piece.

Let’s get one thing quickly out of the way – both of these lenses are amazing. Image quality from either is incredible. Where they do diverge is in their unique rendering and certain physical attributes, and these differences make it easy to understand why Zeiss continues to offer both options.

Physical Characteristics

A hallmark of any of the lenses in the Zeiss ZM line, build quality and a compact form factor are second to none. Intended for use with the ever-gorgeous Zeiss Ikon ZM rangefinder (ZM denoting Zeiss M-mount), both of these lenses work beautifully on that camera and on any M mount body. But be careful, because choosing one over the other may have a significant impact on the ergonomics of your machine. Let me explain.

Both of these little pocket rockets are designed with six elements in four groups, but the Planar’s slightly slower maximum aperture of F/2 means it isn’t as wide as the Sonnar and it’s F/1.5 glass, nor is it as heavy. The Planar weighs in at roughly 230g and the Sonnar at 250g – and while this is certainly a difference, it’s a difference that I never felt in any real way. What’s more noteworthy is the counterintuitive nature of the lenses weight and size and balance. Yes, the Sonnar is heavier, but it’s smaller in an important way.

Where things get wacky is the effect the Planar has on the balance of the camera. Its 68mm length (compared with the shorter 45mm length of the faster Sonnar) means that the lens protrudes from the camera body to the point where it can cause lighter weight M mount bodies such as the CL and CLE to feel significantly front-weighted. While this may not be a terrible problem while the camera is hung from the neck, it may become an inconvenience in certain situations. But this only impacts smaller M mounts; mounted to those lead brick Leica M bodies, a bit of front weight shouldn’t be an issue. The Sonnar, on the other hand, feels perfectly balanced and compact (as its ‘C’ designation would imply).

Aside from these subtle dimensional differences, blind hand held tests show the lenses are indistinguishable from one another. As with the rest of the ZM lineup, every aspect of these two fifties emanates quality. Precision third-stop aperture clicks fall into place crisply and create a sense of satisfaction with every adjustment. Both lenses function identically save the extra stop on the Sonnar (F/1.5) and extra stop down (F/22) found on the Planar. Focusing rings are smooth and well-damped, and laser-etched indices are precise and informative. As expected, there is no difference in the usability of either lens.

But there are additional considerations when comparing both lenses. One being that the Planar is a modern design, able to close focus up to 2.3 feet whereas the Sonnar has a minimum focus distance of 3 feet. Additionally, filter ring sizing may prove challenging as the Planar uses an unusual 43mm size, with the Sonnar favoring the more common 46mm. The hood bayonet is rock solid and well designed, giving the shooter peace of mind in knowing that their hood won’t fall off when wielding their camera in any environment.

Image Quality

There are a small number of premier lens manufacturers pushing out great products at a premium price, but Zeiss’s value proposition is a difficult one upon which to turn a blind eye. When it comes to optics, Uncle Carl don’t play. So why does Zeiss offer two somewhat identical 50mm lenses? These lenses may appear similar on paper, but their results are unique enough that one or the other will be more suitable for certain types of photographers.

The easiest way to see these unique renderings is to view a few side-by-side comparisons.

All shots in these galleries were made on Kodak Portra and Fuji Acros film. 

The Sonnar’s C designation not only implies its compactness, but also its classic rendering. It was designed to emulate the coveted Sonnar 1.5 from the 1930s, the fastest 50mm lens of that era. In the attempt, Zeiss created a worthy successor, one that generates truly gorgeous bokeh and whose results are woven with the spirit of a bygone era. I found images shot wide open (F/1.5) or at F/2 not only had a dreamy aesthetic to them, they were also characteristically soft. Softer than I had expected. Additionally, the Sonnar’s anti-reflection coating (denoted by Zeiss’s T* classification) make shooting into the setting sun pure delight, and portraits with this lens are to die for.

But if the Sonnar is the dreamy bokeh king, then the Planar is quite the opposite – more like a surgeon. This thing could resolve the hair on a fly’s legs from 1000 yards. Not really, but I can say that it’s the sharpest 50mm lens I’ve ever used. Even wide open, corner softness and vignetting are surprisingly minimal. Minor barrel distortion is a refrain heard in certain circles, and I’m sure it’s apparent to overly critical photophiles, but to my eyes images appear clean and free of distortion.

Things to watch for

There does exist with the faster apertured Sonnar an issue relating to focus shift when shooting at wide open aperture (where focus is most critical due to shallow depth-of-field). Shots in the viewfinder will look to be in focus, but shots that are taken will actually be one to three inches out of focus, either to the front or rear of subject. Not good. In my testing I found that this issue does in fact exist and is certainly worth noting.

All of the images in this post were shot on a Leitz Minolta CL or Minolta CLE, two cameras with considerably short rangefinder base lengths. I didn’t experience any focus shift with the Planar F/2 wide open on either camera, but the Sonnar F/1.5 certainly suffered on occasion. Both my CL and CLE have perfectly aligned rangefinders, and I ended up missing the mark (focusing anywhere from 1-3 inches in front of my subject) on one in every three shots. Not a deal breaker by any stretch, it just means being cognizant of focusing carefully, taking more than one frame to ensure you get the shot, and knowing your camera. Naturally, when focus is achieved wide open, it’s a thing of beauty.

Another less than ideal circumstance is the optimization of the Sonnar by Zeiss in Germany for apertures between F/1.5 and F/2.8. Early versions of this lens were optimized for F/2.8 and higher, which required users who wanted to capitalize on their new bokeh-maker to send the lens to Zeiss to have it altered for lower aperture optimization. That was a hassle, however, all new Sonnars being sold today are optimized for shooting wide open.


Finding the perfect 50mm lens can be a very gratifying moment in any photographer’s journey. It’s a discovery that reflects personality and taste, and for many, 50mm is the “desert island” focal length – a do everything lens. Between these two lenses, my choice is clear – it’s the Sonnar, but that won’t be true for everyone.

When it comes to M mount cameras and lenses, I always try to combine for maximum compactness (the majority of my M mount shooting is done on the street), and the Sonnar simply provides a tighter package. What’s more, it does so with virtually no loss in image quality once we reach a certain aperture. From F/4 upward, both lenses’ sharpness and characteristics appear equal in my eyes. They’re both super sharp and create images that are gorgeous. The fact that the Sonnar F/1.5 offers that one stop wider aperture for portraits is a simple bonus.

The Sonnar F/1.5 is a people lens that’s capable of everything else, and the Planar F/2 is a general purpose lens where pixel peeping is of the utmost importance. Both are excellent performers at a reasonable price, $1260 for the Sonnar and $900 for the Planar. Whether or not that extra click of the aperture dial is worth an extra $360 will depend on your style, your needs, and of course, your budget. But whichever you choose, expect to fall in love with either of these amazing fifties.

Want your own Zeiss 50mm?

Buy the Planar F/2

Buy the Sonnar F/1.5

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Dustin Vaughn-Luma

An experience designer, freelance photographer, and competitive cyclist living in San Jose, California with his wife, three sons, and neurotic bernese mountain dog. The majority of his personal work is shot on 35mm and 120 film, and is developed and scanned at home.

All stories by:Dustin Vaughn-Luma
  • I have had the ZM 50 Planar for many years. I used to do quite a lot of technical photography and museum archival work. This was my “go to” lens along with a 65mm/f3.5 Elmar Mk.2 for close up and macro work on a Visoflex III and/or Novoflex bellows. The 50 ZM Planar has a wonderfully flat focus field, which makes it great for taking photos for insurance purposes of things like antique books and paintings. I was so pleased with the Planar, that I thought for some time, I might buy a ZM Sonnar 50/1.5 but instead I bought a Contax to Leica M adapter to use my 1954 5cm f1,5 Opton Sonnar off my Contax IIA, on my various Leica M cameras. The problem is that on the adapter, it focuses “the wrong way round” and after close to 60 years of using Leicas, since I was old enough to hold one, I just can’t get used to that. I also have an 0.95 Noctilux for a fast 50. The older Sonnar however, is an excellent performer with good contrast for the period, even wide open. It is massively sharper and contrastier wide open than my slightly later (1958) Leica 5cm/f1.5 LTM Summarit, and a better all rounder, apart from the more charming OOF rendering on the Summarit.


    • I too was very surprised how well the old Sonnar renders. Really sharp even without it’s age taken into account. My old Summicron Rigid does the casual 50mm work with it’s astounding resolution. Occasionally I would like a more modern look after trying the Summarit 40mm 2.4 from a Minilux. It’s the colours the older lenses are missing.

    • Thanks for contributing, Wilson. I can certainly see how the Planar would be awesome for archival purposes. It’s too perfect! Definitely jealous of those lenses of yours. Maybe one day we can get our hands on an older Sonnar (or perhaps a Noctilux as well) for review.


  • Merlin Marquardt July 7, 2017 at 11:44 am

    Very nice review.

  • Tobias Weisserth (@polarapfel) July 7, 2017 at 2:53 pm

    One should not be using either of these lenses on a CLE or CL in the first place. First of all, the camera size/weight ratio of body to lens – as you noted. Then, more importantly, the viewfinder on either of these cameras doesn’t have the correct frame lines. Framing is experience and guess work then – why buy expensive precision optics if you have to guess? Also, the viewfinder magnification on these two bodies is optimized for wider focal lengths.

    You really want to use either of these two lenses on the best M body for the 50mm focal length: the M3 and only the M3. It has the best finder for that focal length, supporting the focal length frame lines, bright viewfinder patch and a near perfect magnification of more than 90%. Also, the M3 has the longest rangefinder base length of any M compatible body – the M3 accepts focal lengths up to 135mm with supporting frame lines and was built to focus precisely even to those focal lengths. When you buy such fast lenses and such long focal lengths (yes, in the M world, 50mm is a long focal length!), you really need the M3 to take advantage of the fast apertures these lenses offer to get consistently sharp and in focus images. Otherwise, don’t bother. You can just as well spend less money and get a fast Voigtländer for considerably less money and still achieve the same results.

    It would have been better and adequate to base a comparison of these two lenses on using a M3 instead of the CLE and CL.

    • Thanks for the comment, Tobias. While you are correct about both the CL and CLE not having appropriate frame lines for these, I would argue that it is indeed perfectly acceptable to use these lenses on these bodies. I’m taken some of MY favorite images with them. I even have them framed, at home, on shelves. What’s even more outrageous is that I often use my biogon C 35/2.8 on my CLE and find that the 28mm frame inside the CLE viewfinder is just over the true 35mm full frame of the lens. People on the street bug me all the time about it. They giggle and whisper, but I don’t mind.

      FWIW, I own a Zeiss Ikon ZM (the camera in which these lenses were truly designed for), and I can assure you, that if it wasn’t for the camera being off for repair during the testing window, I would have made absolutely gorgeous images with it as well.

      Thanks for the insightful lesson and enjoy that M3 of yours!

      • The Leica CL has framelines for 50mm lenses- they are even marked “50”. Although I have not used the C-Sonnar on mine, the Canon 50/1.5 Sonnar formula lens is a perfect fit on it, small enough to fit in the pouch case. Focus is not hard, even wide-open.

  • Excellent article Dustin. Very enjoyable read and you make your points so well.

  • Well, I tried both Sonnar and Planar when I was looking for a fast fifty for my M2. I liked Planar bit better as it seemed to me, that at 0.7m at F2 it really made the subject pop out. But in the end I went for vintage Canon 50/1.4 LTM lens as you know, it goes to 11 😀

  • Zeiss isn’t the only company that produced a Sonnar formula lens and a Double-Gauss lens in the same focal length: Canon did the same with the early 1950s Canon 50/1.5 Serenar (Sonnar) and Canon 50/1.8 Serenar (Double-Gauss). These days you can purchase both of these lenses for under $400, about $250 for the F1.5 lens and $150 for the F1.8. The later Black-barrel 50/1.8 changed the type of glass used, often subject to haze and etching.

    Would be an interesting, and less expensive, follow-up to this article.

  • Well, since I’m looking for a 50 to mount on a CLE, I’m glad you tried these out. I have to say, I’m impressed you managed to hit focus at all when you were using the Sonnar wide open–Were you using a tripod? And, you say that the planar is too front-heavy in some situations–Like what?

    Also, as for the framelines–Did you frame just a little tight on the 40mm framelines? As someone who has ever tried it, I am a bit apprehensive about this…

    Thanks for a wonderful article!

  • so I bought the planar to use with my m3 after reading this article and a few other reviews . it was sooo cheep compared to the summerit 50mm I was looking at. I bought mine used for 600. I have had it for about 6 months. I thought originally that I wanted something really fast like a 1.4 or that Voigtlander 1.1 or the sonnar but after using my planar along with a Voigtlander 35 2.5 and a summaron 35 2.8 I can honestly say I can 100% get away a slightly slower lens. I just use more tmax and push it to 800 or 1600. and really only shoot color 50 iso – 400 during the daylight anyway. I shoot a lot in bars or goofing off with friends and used a nikkor 50 1.2 for that mostly and after switching to using the Leica I really don’t miss the speed. I hit focus more with the planar wide open more than I ever did with the nikkor. my only real complaint is it does feel a little cheep compared to the summaron I have. But the older Leica lenses are the best made lenses I have ever used. I also really don’t like the fact that the Zeiss lenses and the Voigtlander lenses have the same shiny hood mount. I would rather have a screw in hood that have that shiny thing. oh and the lens caps are the worst ever! normally I would just leave the caps at home but I am paranoid I will burn a hole in that cloth shutter. But after all the little things I don’t like, It is still 1000 times better made than any nikkor g type I have used.

  • The Zeiss Planar design s over 30 years older than the Sonnar…

  • All the time: great reviews here.
    I am not a brain-washed Sonnar persons who will replicate Sonnar for every lens, despite this one of the best formula.
    I will just say that when it comes for ZEISS: it is never wrong, it is a minimum minima: very good to excellent. Zeiss is better than Leica, and the Zeiss lens made today in Great Japan by Cosina are sometimes cheaper than some new brands made in dictature.
    There, Planar or Sonnar, very easy : you want bright, clean, sharp images better than Leica go for the Planar, you want a high artistic character lens go for the Sonnar!!!

  • A bit late to the party on this thread but I thought I might leave my findings. I bought the Sonnar and played with it for a few weeks before I used it on a commercial job for the first time. Totally disappointed and resulted in me having to re-shoot. Very embarrassing. The majority of the shots were shot in an old barn in the afternoon, with strong backlighting from the sun. The purple fringing was the worst I have ever seen, I couldn’t show them to the clients. Sold that lens as quick as I could. I currently have the Planar, a very competent lens, but very clinical and somewhat boring. It’s probably been over two years since I’ve picked it up, preferring my Summicron. For the price, it’s a great lens.

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Dustin Vaughn-Luma

An experience designer, freelance photographer, and competitive cyclist living in San Jose, California with his wife, three sons, and neurotic bernese mountain dog. The majority of his personal work is shot on 35mm and 120 film, and is developed and scanned at home.

All stories by:Dustin Vaughn-Luma