Zeiss 50mm f/1.5 C Sonnar ZM
The Lens People Love to Hate
By: Mikael Törnwall
There are few lenses that are more hated and more loved than the Zeiss Sonnar C 50mm. Some photographers love the lens for its smooth bokeh and great 3D images, some hate it for its soft edges when shot wide open, and for its focus shift issues. I have been in both those categories.
I got the lens a couple of years ago for my Leica M8.2 and I kept it when I upgraded to an M9. I have to admit I did not give too much thought to it when I first bought it. An almost new, f/1.5 normal for $750 felt like a bargain compared to a used Summilux 50, and definitely compared to a new Summilux.
It quickly turned out that the lens had something extra, a classic look and feel to the pictures that few modern lenses can compete with, at the same time that its supersharp stepped down to f/5.6 or f/8. That’s thanks to the combination of Zeiss using the 70 years old Sonnar design as a starting point for a modern lens, while still using contemporary coating. For instance, you see none of the flare you would normally expect from and old design.
There is something else that the Sonnar and some other Zeiss lenses have, and that is a very pleasant 3D feeling to the pictures. It´s not as clinical as pictures with some of the ASPH-Leica lenses sometimes can get. It just feels very pleasant, for lack of a better word.
I would go so far as to claim that the combination Leica M9 and Sonnar 50mm sometimes is capable of producing results that can rival my Hasselblad film cameras with 60 by 60 mm film.
So, why did I not love the lens unconditionally from the beginning? The reason is the focus shift issues that the lens is infamous for. At f/1.5 you can easily be off by more than an inch shooting a portrait from 1,5 meter. That’s a lot with the very short DOF. So I found myself with three options, to send the lens back to Zeiss to get it optimized for shooting wide open. But that had left me with a lens off focus at f/4. Or I could try to figure out how to get it right with the focus shift, or just sell the bastard and buy a Leica instead.
I was actually moments from doing the latter. I had even created an ad for Ebay, when I looked through a set at my Flickr-account showcasing the Sonnar at its best, when I had second thoughts. I realized I was about to give up a lens that often produces great results and every now and then is unique and totally outstanding.
The trick to manage focusing with the Sonnar, is to lean forward an inch or so, when taking pictures close up and wide open. Since I started using this technique I get most but not every picture sharp.
The nice thing is that you almost get two lenses in one if you buy the Sonnar, a very pleasant dreamy look wide open and a very sharp one at f 5.6. I would get an even sharper lens for the same money if I got a Zeiss Planar 50, or an used Leica Summicron, but in most cases the Sonnar is sharp enough.
And sometimes it can produce images that neither the Planar or the Sumicron can come close to.
Mikael Törnwall is a Swedish journalist and semi professional photographer, that has spent the past four years in the US. He has been documenting America with his camera both for his newspaper and for himself.
In 2007 I tested the Zeiss 50mm f/1.5C Sonnar on a trip to Morroco. Following the trip we inquired of Zeiss about some of the optical issues that we were seeing, and received this response. It goes a long way toward explain this very special lens.
Information about special features for dealers and users
The C-SONNAR T* 1.5/50 ZM is a very special lens; based on a classical lens design concept from the 1930´s. The additional letter “C” in the name of the lens expresses this designation.
This lens design helps to achieve pictures with a special artistic touch. This lens ‘draws’ your subject in a fine, flattering manner and is therefore ideally suited for portraiture. It renders a sharpness that is slightly rounded, being less aggressive than in contemporary lens designs, but at the same time not soft in its rendition.
Many famous portraits of glamorous and prominent people during the 1930´s used this technique to great effect. These images are characterized by portraying the person in a shining, nearly celestial way. This effect is very well balanced and not exaggerated; therefore many viewers see it in a subconscious way. The trained observer, however, understands the underlining technique and enjoys the results.
This lens design exhibits some additional effects, which should be understood to achieve the maximum benefit from the C-Sonnar T* 1.5/50 ZM:
Because of the above mentioned classical characteristic of the lens the best focus position in the object space can not be kept exactly constant for all f-stop settings. The passionate photographer might notice a slightly closer best focus in his pictures than expected. When stopping down the lens to f/2.8 or smaller this effect is minimized, so the focus position will be as expected. In order to balance the performance at full speed and other f-stop settings the lens is adjusted with above described characteristic.
The special features of the C-SONNAR T* 1.5/50 ZM are best used in emotional, artistic, narrative images, portraits or atmospheric landscapes. For documentation or technical subjects CARL ZEISS recommends to stop down the lens at least to f/5.6 or to use the PLANAR T* 2/50 ZM lens.