To some the picture above is some camera porn. For others it is a travesty to have a Zeiss lens on a Leica camera. To a Leica diehard the selection of a Leica camera is done in order to shoot their amazing glass. Let me explain why I love to shoot Zeiss 35mm f/2 ZM on my Leica M6 and ME.
We all know Leica makes amazing glass and we all understand that it is expensive. It would be very simple for me to point to the high cost as an underlying reason for moving to Zeiss but my decision is not that simple. Here is the thing...I LOVE Zeiss glass. Full stop. Lets leave the price discussion for the very end shall we?
I love the build quality of Zeiss. These lenses feel heavy, precise and perfectly balanced. When I pick it up I get the feeling of quality. I get the same feel with a Leica lens. I see no difference in their build quality. So lets call this part of the evaluation a tie.
Aperture is key on a ZM lens. Since you select the aperture on the lens itself you should feel comfortable with the aperture ring. With the Zeiss lens I have ⅓ stop selections. I like this as it gives me plenty of room to fine tune the exposure. With Leica I get ½ stops. Not a deal breaker but I prefer the fine tuning of the Zeiss. The feel is very different as well. The aperture ring on Zeiss requires more pressure to change. Leica, just like my Voigtlander, has a much smoother aperture. Now "smoother" is not always a desirable quality. On the focus ring it is desirable but on the aperture ring I prefer to have it stay where I put it. On the Leica I have to check to make sure it has not accidentally changed. This round goes to Zeiss.
In terms of size, Leica has the Summicron lens which is smaller and does not block the viewfinder. The Zeiss does. So this round would have to go to Leica. The fact is that if you shoot the M system you will have some lenses that block the viewfinder. The fact that on the 35mm lens you have see the full view is interesting but I do not put too much weight on it.
In terms of optical performance we have an interesting story. From what I have read, the Zeiss is better than Leica. At worst lets call it equal. But here is the issue with Optical Performance, it does not weight that much. If a lens is poor then I clearly do not want it. But the fact that this Zeiss might be 5% better than Leica it would not justify the choice. With such a great lenses the minor difference is not normally visible. So while Zeiss edges Leica by a hair it is not worth really discussing it.
Unfortunately I do not have any images using the 35mm Summicron but I do have some from the Leica 28mm Summicron. Since the focal lengths are so different, and wider angle lenses are harder to make, I do not want to compare the lenses (although the 28mm Summicron is AMAZING) but do want to show how solid of a performer the Zeiss lens is.
Here we have the Zeiss 35 f/2 ZM shot at f/2. I did not crop this image and very light post processing in order to show what the lens can do. You can see the buttery smooth bokeh and the lack of color fringing or chromatic aberration. Colors are bright and it is plenty sharp.
The picture above is from the Leica Summicron 28mm at f/2.8. This is an amazing lens and you can see that it is very close to the Zeiss. Obviously the 28mm is a tougher focal lens to make than a 35mm.
Here is the bokeh of the two lenses. Both are very nice but there is something about the rounder bokeh of the Zeiss. Again both are very nice.