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

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.

Sonnar at F/1.5

Sonnar at F/1.5

Sonnar at F/2

Sonnar at F/4

Planar at F/2

Planar at F/2.8

Planar at F/4

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.

Focus shifted with Sonnar

Focus hit with Planar

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.

Takeaway

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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