Zeiss Jena f/1.5 Sonnar vs. f/2.0

Hi,

 

I've gathered that the consensus around the internet is that, aside from being faster, the 50mm Zeiss Jena f/1.5 Sonnar lens (for Contax rangefinders) yields better/sharper images than its 2.0 counterpart. My question to owners of both lenses is how pronounced is the difference to you? I would also appreciate it if someone could outline why the 1.5 Sonnar produces better images from a technical standpoint.

I couldn't tell you about the technical differences that might affect performance, but I can tell you that my samples of both lenses provide excellent images. I haven't made really large prints from them so differences might be more apparent if I had. One thing you might consider if you are choosing one over the other is the f/stop range--all of the samples of the f/2 version that I have seen stop down to f/22, while pre-war f/1.5 versions mostly stop down only to f/11. There are some early versions that only stop down to f/8. With Tri-X or HP5 that could be limiting in bright light situations without using a neutral density filter.

I don't believe they would be better, unless of course the f1.5 is somehow more durable, which again I don't believe, or has been better cared for because it would have been more expensive, which is logical. I think coating would have been introduced for each version at the same time.

I have a pre war rigid Sonnar f2 on Contax I that is clear as a bell.

I would also be interested if someone could account for this perception.

From what I've read, the f/1.5 has a pretty particular rendering at the wide apertures, which makes it desirable. But I never read they're sharper as such, so nothing suggests to me it renders a better image in the technical sense of the word. Possibly in the esthetic sense, but that's far more subject to taste of course.

 

Can't vouch for either one, but the best of my 2 Jupiter-8 (~ Sonnar f/2) lenses is a solid performer.

my small collection of more-or-less Contax RF-mount is the following:

 

Contax RF Zeiss Oberkochen Opton-Sonnar *T 50 1.5 [the real thing]

Contax RF (Arsenal) "Sonnar 5sm f/2" née Jupiter 8 50 2.0 [a converted to Zeiss Soviet lens]

Contax RF Arsenal Helios-103 53 1.8

Contax RF Arsenal Helios-103 53 1.8

 

Contax-Nikon RF Nippon Kogaku Nikkor-S-c 50 1.4

 

The astounding thing to me is that all of these perform very well to superbly.

The Helios-103 is said to be a Summicron-inspired design, but it is really more a Biotar IMHO. It's probably the biggest bargain ever in Contax RF lenses.