#365. Zeiss C-Sonnar 1.5/50 ZM (on Sony A7r): Moody Modern Retro

By pascaljappy | Review

Jun 14

GAS warning! Do not let this lens grow on you …

A week ago, having finally gotten to terms with the fact I no longer owned an OTUS 85, I received this C-Sonnar 1.5/50 ZM lens from Zeiss. And what a joy that was: finally a lens I really didn’t like. Finally an opportunity to say something bad about Zeiss and not sound like the born-again fanboy.

Jewel lens

Jewel lens

Out of the box, it looks drop-dead gorgeous. More jewelry than optical instrument, particularly with the lens hood attached. Perfect weight, perfect size, perfect looks. It matches the purposeful design of the Sony to a T. So unbearably Fab.

But on the camera, oh joy of joy … It. Was. Terrible.

Overly firm and gritty focusing, lack of contrast, overly long minimum focusing distance, poor corner compatibility with the A7r, dark and dull images. Review over, that was easy: Zeiss please remove this rubbish lens from your catalog, this is 2015.

The rear light of a red convertible photographed with a Zeiss C-Sonnar 1.5/50 ZM on a Sony A7r


I shared my concern with the French importer, who explained: this 1930’s design was updated in the early aughties but aesthetics have not been altered at all in the process. He told me how the design was similar to the crazy f/0.7 lens used by Stanley Kubrick to film Barry Lyndon and how CNES uses this lens in space.

His recommendation: Not your average look, not your average lens. Think it through.

I did. And there goes my reviewer’s neutrality cred, right out the window.

I’ll get to the real review shortly but, before that, let me explain what’s so interesting in this lens. My love for the OTUS came from the control that lens offers its owner over highlights and atmosphere. It’s nearly impossible to burn a highlight using an OTUS and I used my sample between +1 and +3 stop all the time. The 50/1.5 ZM is quite the opposite. It has a strong signature that can be  hard to work around, burns anything vaguely bright faster than toast and focuses much more on mood than on perfection. It is both low(-ish) contrast and high in colours. And the natural tendency of the lens is to create slightly dark images. However, this needs to be qualified:

  • Now that I’ve taken the time to make a few more photographs, it’s possible to alter the mood to light and airy, while retaining the soft natural rendering of the lens. I’m not sure about all photographers, but models are likely to prefer it to the ruthless OTUS.
A B&W portrait of a young woman in a skirt. Sony A7r and C-Sonna


  • The C-Sonnar absolutely shines in low-light. Unlike the night-owl OTUS that sees through the abyss and makes it look like daytime, the C-Sonnar creates low-light photographs that look like low-light, but with great clarity, colour and 3D. Really lovely stuff if that’s your style.
A stormy sunset in provence. Sony A7r and C-Sonnar ZM 50mm f/1.5


But I’ll get back to both points later. On with the formal review.



Jewel-like build, good looks, 1/3 stop click aperture ring, a focus ring that smoothed out after a few hours … what more need I say ?

This is the result of many years of evolutionary design and it feels good in hand. For some reason, new designs such as the BATIS do away with essentials such as an aperture ring. Go figure.


3D and bokeh

Here’s a scene at f/1.5, f/2, f/2.8 and f/2.8.

3D is spectacular and subjectively feels better at wider apertures. Brilliant.

DSC09750DSC09751DSC09752DSC09753Swirly & bubbly bokeh is not my cup of tea, but it’s not too bad here. There are traces of agitation at wider apertures that get in the way of perfect smoothness, but it’s no big deal. Some actually prefer bokeh with a presence. What matters more is that this lens relays a lot of structural information in its out of focus areas, much like the Distagon 1.4/35 ZM and OTUS 55/1.4 but unlike the OTUS 85/1.4 and my Leica-R lenses.

My sincere apologies for now breaking the implicit code of lens reviewers by including cat pictures. But this one does illustrate the slightly bubbly nature of highlights that can often be objectionable and isn’t too bad here. f/1.4 at night. Again, note how soft this image looks but how clear and natural it appears in very low light.DSC09706-3As you can see in the chromatic aberration section enlargements below, f/2 is a lovely sweet spot (between aperture, aperture shape and correction), particularly for bokeh. f/1.5 displays some bubblyness, probably due to undercorrected optics. f/2 is very nice, with no bright outside edge to out of focus highlights.

From f/2.8 to f/5.6 the 10 iris blades draw dents in the otherwise perfect aperture circle, which appear in oof highlights (see below f/2.8). Avoid these apertures for pics in which highlight bokeh is really critical. Above and below these points, aperture is almost perfectly circular. Nice!

Motorbikes at rest. Sony A7r & Zeiss C-Sonnar ZM 1.5/50

Silent race @f/1.4

But, even at f/1.4 the bubbly bokeh never intrudes when the background isn’t too crowded.


Chromatic aberration

These 100% enlargements speak for themselves.

At f/1.5, some chromatic aberration is present (top). It’s easy to correct and less than what the flagship Distagon 1.4/35 ZM exhibits at similar apertures (compare this in my review of the 1.4/35 ZM)

f/2.0 is excellent and a sweet spot for bokeh as well (middle).

Correction is almost perfect at f/2.8 (bottom).

CSonnar-CA-15CSonnar-CA-20 CSonnar-CA-28


Flare and glare

With the sun in the frame, there is very little trace of flare, even at f/1.5

C-Sonnar 1.5/50 ZM flare test on Sony A7r at f/1.4 with the sun in the frame

Flare at f/1.5


f/1.5 uncorrected


f/5.6 uncorrected

f/5.6 is obviously better than f/1.5, showing better contrast and clarity. But the small flare at center is more visible and more difficult to suppress.

Note that these images are worst-case scenarios (sun flaring on a very dark foreground). Below are two real-life examples that show how good the performance really is.

DSC09775 DSC09774DSC09781



A tricky one, sharpness. The lens isn’t designed for perfect corners at wide aperture, a fact compounded by the relative incompatibility with the A7r,  and it shows abundantly.

Just kiddin'

Just kiddin’

At longer distances, you really need f/8 for a sharp photograph.

At closer range, this is one sweet lens in portrait scenarios or to enhance near-far relationships.

A village fountain in a colourful Provence village. Sony A7r & Zeiss C-Sonnar 50/1.5 ZM

Atmosphere, Atmosphere

And what’s wrong with that ?

The best tools are those designed with a clear purpose in mind. A generic car isn’t designed for carrying many people, wading in the mud, screaming  round a track, shining chrome at an exhibition or spinning doughnuts. That’s a utilitarian and boring car. A 67 L-88 Corvette is terrible off-road and no one would criticise it for it. A Porsche 918 won’t take your 4 kids to school in great comfort. And who would blame it for it? Both are fantastic cars in their own right.

Yet, it seems the consensus, when it comes to photographic lenses, is that they should perform flawlessly at every aperture in any conditions. Not so. The shortcomings in a lens can indicate poor design (as in too many cases) or a clear purpose.

It takes only a few seconds of looking at the C-Sonnar’s MTF curves to realise the use case for this lens is not ultimate corner sharpness at infinity.

Zeiss C-Sonnar ZM MTF curves

(c) Zeiss. Click to access technical documentation

This is what Zeiss’s website says about the C-Sonnar : “The standard focal length offers special qualities, which make it well suited for portraiture and documenting authentic events and people.” Which makes sense, when you use the lens. It really is all about atmosphere and documenting mood and people.

So, it’s a specialized lens, in which corner sharpness doesn’t play a major role. That being said, it’s very decent closed down between f/2.8 and f/8. And pretty good, even at f/1.5 in the center. See photo below, and 100% enlargement.

A black motorbike photographed with a C-Sonnar 50mm f/1.5 ZM Zeiss lens

Praying Mantis

Dash100Here’s a full-size image (at f/5.6) to download for pixel level inspection. You might recoil at what you see or be satisfied that, at 12″-16″ print size, it’s every bit as sharp as the FE55/1.8 (which has nowhere near as much character). Horses for courses …

King-size Cedar (click for 100% file)

King-size Cedar (click for 100% file)


Distortion ? What distortion ?



Excellent. Lovely colours, although not quite as subtle as the Distagon 1.4/35 ZM, probably the world’s best in that respect.

The moody nature is evident and responds well to post-processing that enhances that feeling.

Hay fields in golden light in Provence,Zeiss C-Sonnar 1.5/50 ZM

Hay Hay Hay


Porker pie

Sony A7r & Zeiss C-Sonnar 1.5/50 ZM. A fountain dripping on a sunny Provence evening.

Fountain dew

The lens seems to express itself much better in low contrast situations, where it extracts every last drop of natural colour and reproduces it with an earthy pastel quality. More Gibson than Fender.

Here’s a variety of colours in gentle light.




Red diagonal


Mauve at night



The C-Sonnar excels at creating somber atmospheres. If the Distagon 1.4/35 ZM is Mozart, then this is more Beethoven. Colours seem “dense”. Think of the density of Chateauneuf du Pape, of vinyl played through tubes and Spendor speakers, as opposed to rosé with ice cubes or YouTube played through earplugs, which is what you get with some lenses more focused on resolution.

Unfortunately, the C-Sonnar stumbles in bright, high-contrast scenes (see below).  Highlights seem muted and unnatural in these conditions, so it’s best to underexpose and salvage shadows in post-processing.

High-contrast landscape photograph with a Zeiss C-sonnar 1.5/50 ZM lens


With that in mind, it’s possible to work the image out of the somber-mood register, but it’s probably best to use the lens for what it does best: atmosphere.

Torn wall in a multicolor design shop. C-Sonnar 1.5/50 ZM.


A golden light in a design shop - C-Sonnar 1.5/50 ZM

Gold Vador

A spherical light bulb in a design shop. C-Sonnar 1.5/50 ZM

Bokeh bulb

The back garden or an oriental design shop. C-Sonnar 1.5/50 ZM




Place des Prêcheurs - Aix en Provence

Place des Prêcheurs


Black and White

Storm clouds over Provence - Sony A7r and Zeiss C-Sonnar 50/1.5 ZM

Provence, copping it again …

As I hope this photograph demonstrates, the C-Sonnar 1.5/50 ZM is a brilliant lens for black & white.

Brilliant, with minor reservations.

DSC09757-ModifierAs discussed previously, the natural tendency to blow highlights means you’ll often be shooting at “darker settings” (less exposure) and adjustments in PP will become visible a that much earlier.

Compared to a no-compromise design such as an OTUS, the C-Sonnar offers less tone control. You’re left to play with a “smaller dynamic range”.

DSC09780-ModifierStill, the low contrast feel is again wonderfully atmospheric and, when the exposure range isn’t too wide, produces lovely tones. The photograph above is a perfect illustration. Just 3 roofs catching the evening light. The photograph in colour is totally uninteresting. Converted to B&W with little or no digital work added, it just sings Provence.DSC09763-ModifierWith a yellow filter on yellow flowers and a little clarity enhancement, it’s possible to make the look more modern and peppy. But the look remains natural and laid-back with no harshness anywhere.

DSC09760-ModifierSo there you have it. Less incisive than the Distagon 1.4/35 ZM and less in control than the OTUS, it produces files that hint at Douasneau more than Adams. I feel that fits the marketing claims rather aptly.

Regular cloud patters over Provence hills. Sony A7r, Zeiss C-Sonnar ZM 1.5/50mm

Cloud slices



Let’s see. Focus shift. It won’t bother you on a Sony A7x but will be a pain on rangefinder cameras (so much for the purity argument).

Blown highlights. This one puzzles me. The lens feels distinctly low-key, soft and low-contrast (in a good way) but acts high-contrast in that it blows highlights like a 1990’s digicam … See the tree trunks at bottom and sunlit walls in the fountain photograph above.

Focus breathing. It’s one of the more pronounced cases I have ever seen. Almost comical. For the price of a prime, you actually get yourself a zoom that breathes so much it seems alive. But that will only matter to videographers with no sense of humour 😉

DSC09867 DSC09866

Weird bokeh artifacts. By the same principle that creates bubbles around out of focus highlights, f/1.4 can play strange tricks along contrast edges. In the second cat photo, above, my wife’s nose is literally cut in half by the bokeh if any contrast enhancement is added. Who does that to innocent women? A little more irksome, but entirely avoidable by aperture choice.

That’s about it and it matters little compared to what the lens does perfectly.



At the end of the day, this is a lens with a strong personality. Not really my style, but gorgeous nonetheless.

The last drops of sunlight trickling through the ocher walls of a Provence village. C-Sonnar 1.5/50 ZM.

Last drops of light

I particularly love the way it clings to clarity and colour in low-light situations and makes them come alive.

My only real criticism is that controlling highlights is a real pain in some situations and photographs in high-contrast situations aren’t that great. Highlights, even when kept in check aren’t  anywhere as beautiful as darker areas.

Also , in spite of the official claims to great bokeh, I don’t always enjoy it. Definitely not as obtrusive as others, it has a slightly gritty quality that occasionally spoils the ambiance that other aspects of the lens conspire so brilliantly to create.

OOF roots showing the bokeh of the Zeiss C-Sonnar 1.5/50 ZM lens

Okay bokeh. Just Okay.

Apart from that (and the design that’s not all that happy on a Sony sensor) it’s all excellent news.

And, in spite of all that talk about darkness and strong personality, the C-Sonnar 1.5/50 isn’t a single trick pony. Close it down and you have yourself a very competent landscape lens.  DSC09824 DSC09803-2 DSC09801It’s also a beautifully designed lens, built like a little jewel that brings with it a strong and endearing personality (that tight focusing ring loosened up and became firm but silky smooth after a little while).

It’s a mature lens for a mature shooter. That is anyone taking the time to know the lens and learn to use what it does best and avoid the known idiosyncracies, and favours atmosphere over test results. Add points for M-camera owners. If that describes you, the C-Sonnar will put an endless smile on your face!

Enjoy, written in neon. C-Sonnar 50/1.5 ZM


Email: subscribed: 4
  • Frederick Hartman says:

    I’m enjoying your lens review. I appreciate your experience and good taste. I’m looking forward to more but I suspect it’s going to cost me a fortune!

  • Sean says:

    Hi Pascal,

    I have this lens and really enjoy its idiosyncrasies.

    Purely as informative, here’s my Flickr album of images I have taken using this lens:




    • pascaljappy says:

      Sean, you’re a man of good taste 🙂 Some really excellent photographs in that Flickr page, thanks for sharing. I’m loving the lens more and more. It’s high contrast but soft presentation is addictive in low light. Regards, Pascal

  • PaulB says:


    Nice review. I suggest that you use this lens more and get to know it. You may have too many expectations after using the Otis for so long.

    Since, the more I read of your experiences, it seems that your conclusion may ultimately match the recommendation give by my local Zeiss Rep. Which was, this lens is intended for low light, wide open, and portraits with character; if you are going to do landscapes, stopped down, the 50mm f2 Distagon is the better choice.


    • pascaljappy says:

      Paul, that’s quite right. I’ve asked to keep the lens a little longer to get to learn it a bit better. If the weather begins to cooperate, I’ll make more photographs and post them here. I’m really starting to like it a lot. Pascal.

  • Till says:

    In case you’re still sad about “losing” the OTUS you might want to try one of the ZF Makro Planars or possibly the 135 f2 APO. I’ve heard great stuff about them.

  • Raymond says:

    I love this lens, it’s a fallacy to think that pure edeg to edge perfect sharpness makes for good photo taking..

    I’ve been using this as the very first lens for the A7R, take a look http://jkspepper.tumblr.com/tagged/csonnart1550zm

    • pascaljappy says:

      Really great photographs Raymond. I’d read reviews of the lens before but never really liked the colours or style. Your photographs really bring out that high-contrast shadows and mood. It’s a fantastic lens. I’m buying my review sample.

  • Thomas says:

    Hello folks, very nice review, when the right time is spent, ypu can explore so much in these vintage lenses design. I’m a voigtlander fan, I think you’re almost ready with some nokton or heliar try… take a look there, almost all picture made with those : https://www.flickr.com/photos/nex6sigma/

    thank you for sharing your experience

    • pascaljappy says:

      Thanks for the link and samples. Ironically, it’s much more difficult for me to get my hands on CV lenses than Zeiss. But I do hope to review some one of these days.

      • Thomas says:

        Hello Pascal, if your journey came thru south western France, you’re welcome to try mine, best regards !

        • pascaljappy says:

          Thanks Thomas, that’s very kind. We used to have family in Pau, who now moved to Bordeaux. So I might just take you up on that, sooner or later 😉

  • Mike says:

    I need another 50mm lens like I need a hole in my head…but I love the way this lens renders images. Reminds me of my Voigtlander 40 1.4, but the zeiss looks to be much sharper and has less vignetting. I think this lens is a nice compliment to the FE 55 which is just about perfect. Maybe too perfect.

    • pascaljappy says:

      Oh how I know the feeling … In my efforts to lower my lens count to 2 or 3, I sold my loved but unused Loxia 50 and am selling my loved but unused Leica Summicron-R 50/2. But this 50 has such a compelling personality, I’ve just bought my review sample. Drat! I agree with you about the FE55 being too polite. The FE 35/2.8 was the same and had to go. Both great lenses, but a little more soul is nice in a lens. I suspect the otherwise excellent FE 35/1.4 might “suffer” from the same perfection, as well.

  • Yeahhh says:

    Love the autopsy of this lens very much. That’s why I read this blog.

    • pascaljappy says:

      Thanks so much ! It is apreciated. Sorry about the long delay in responding, I was away out of Internet range for some days. All the best, Pascal

  • Brian Nicol says:

    Eek!!! You made me repurchase this lens, and I was trying to reduce my system to something sensible….

    This is the only lens that I have regretted selling. Three years ago I was transitioning from my Sony A900 system (which I loved, but so heavy and I have a whiplash injury) to the Sony Nex 7 and then to the Leica M240/Sony A7R.

    I purchased the Zeiss 50/1.5 as my first lens for the new system, Sony A7R/ Leica M. I loved the Nex 7, now converted to IR, but eventually I got the A7R when it was released and waited a year for the M240 to arrive. 50 mm was by far my favourite focal length and I discovered I had managed to collect four 50mm or equivalent lenses during the transition (leica 50 1.4 ASPH, Zeiss 50 1.5, SLR Magic 35 T0.9 for Nex (gorgeous wide open creamy smooth bokeh, but Big and Heavy), and the Sony 50mm 1.4 ZA). I had the Leica 35 1.4 Asph but did not get on with it so replaced it with the Zeiss 35 1.4mm to save money and got one of the first ones and have hardly taken it off my Leica since getting it – I love its rendition. I eliminated all 50mm lenses except for the SLR Magic thinking I can crop the Zeiss 35/1.4 images for the times when I need a 50mm with high resolution across the frame. However, I have a painterly style and have missed the Zeiss 50/1.5. It certainly is not a general purpose lens and often gets terrible reviews by people looking for perfect high resolution glass instead of appreciating artistic rendition for different purposes. As you are aware, there is an excessive emphasis on resolution in the reviews on the internet instead of the overall rendering of the lens for different applications and personal preference.

    I have just ordered a used mint copy of this lens with the expensive accessory hood and cannot wait to get it again. The initial mistake I made with this lens was shooting it always at f1.5 and I did not like the out of focus highlight rendering. However, as described, the f/2 rendering is magic especially when there are highlights. It is also a fabulous portrait lens and certainly not a hard light mid-day lens: hey, it is an amazing artistic specialty lens that is usually reviewed by incompetent reviewers on the basis of a general purpose 50mm! This is a lens that feels great on the camera, in use, discreet, and makes you want to got out and take pictures, creates unique wonderful images when you master it; isn’t that the real joy of photography?

    • pascaljappy says:

      Aah, it seems that we share similar tastes in lenses 😉 The 1.5/50 ZM and 1.4/35 ZM are my two favourites and leave very little room for the others. Sorry I made you spend your money on this again. I sure hope you enjoy your time with your second sample. What is the NEX 7 like when converted to IR ? Sounds moutwatering. Cheers, Pascal

    • Martin says:

      I, too, love this lens. It is especially nice with film. The 35mm 1.4 Zeiss ZM not only sounds nice, it rimes with it, but the price point is too high. The Sonnar can be had quite reasonably. Other than the Voightlanders (with which I’ve had no experience), it’s the least expensive fast lens for M-mount.

      • pascaljappy says:

        Yes, the 35/1.4 ZM is quite pricey and its look is quite different. More neutral and less saucy 😉 Both are great lenses and work even better with the new Sony than with the previous. Lovely stuff. I used to own a 35/2.5 Colour-Scopar from Voigtlander. It was tiny and very lovable but only if you like the colours and specific rendition. I’m sorry I sold it. But I don’t know the others.

  • Mark Muse says:

    Consider the ZF 50 Makro-Planar. Wide open it is dreamy, moody. By 5.6 it is brilliant. And of course it is a macro too. A very versatile lens.

  • George says:

    This lens needs to be mastered and tamed… On the rare occasion that you / I can the shots are extra terrestrial especially the 3D pop….

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