Do All Sonnars Give Similar Look?

[Sonnar2]

Both Ernostar and Sonnar are derived from the Triplet lens design family, or to be more precise: from a triplet with inserted element between the first and second lens, like the Gundlach Ultrastigmat (4 single elements) probably known by Ernemann and shown as "basic Ernostar design", AFAIK, by Robert Kingslake (History of optical design). In order to reach a lens corrected for high speed, he did two different things with it in consecutive order: first (1923), splitting the first and second lens into a cemented pair (resulting in the Ernostar f/2). Second, 1924, splitting the first lens into a triplet, resulting in the f/1.8 lens, still having 4 optical groups and therefore, somewhat resistant to flare. This later lens was predecessor of the Sonnar because of the cemented triplet. This only had 3 optical groups which broadly improved backlight scene behavior.

For a lens that lacks the high speed (like the 2.8/85) you can use the "basic Ernostar type" (or Gundlach Ultrastigmat type, if you prefer) with 4 elements. I found my Rollei 2.8/85 with 4 elements (although pleasing) slightly soft wide open, so I can imagine what happen if you stretch this design to f/2. That's why Ernemann varied it. Pentax did stretch it to f/1.8 in 1960, with coating and 5-element design, but this quite soft wide open too...

 

[darkkavenger]

I thought the 135/4 J-11 was a Triotar design...

 

[BJ Bignell]

Assuming you compare Sonnars of equal focal lengths, it's likely that there are similarities in performance which could be identified as characteristics of the design. Also, lenses that are closer in age to each other are more likely to have similar designs, so there will probably be a stronger resemblance between these then there would be between a 1930s Sonnar and a 1990s Sonnar.

However, not all "Sonnars" are really Sonnars, just as all "Planars" are really Planars. There was a discussion about the naming of the new ZM Sonnar 85/2 some time ago; you can read what one of the engineers at Zeiss had to say about it here: http://www.rangefinderforum.com/forums/showpost.php?p=116526&postcount=36

 

[VinceC]

Raid also mentioned the Nikkor 50mm f/1.5 -- this was also a Sonnar-derived design. Postwar Zeiss claimed it was a direct rip-off -- somewhat understating how difficult it is to copy a lens design and manufacture it yourself unless you have significant optical expertise of your own. It quickly became a moot point -- after a few months production in 1950, Nikon redesigned and improved the 1.5 formula to produce the world's first 50/1.4. It's a lens that still holds its own today, despite a few quirks in flare derived from the Sonnar formula itself. Nikon did a complete redesign in the early 1960s, adopting a planar formula for its final (and rare) RF lens as well as the ubiquitous 50mm f/1.4 F-mount SLR lens.

I have always found the Nikkor 1.4 of the 1950s to have some unpleasant out-of-focus effects when stopped down a bit -- say 2.8 to 5.6 ... it was an intentional trade-off in order to make the lens extremely sharp.

 

[darkkavenger]

I should add to this that I didn't noticed any differences between my 1936 50/2 pre-war, coated, collapsible Sonnar and my 1970 Jupiter-3 50/1.5. Equally sharp, very nice oof areas.

 

[raid]

Max,
Is your Zeiss Sonnar in Contax mount or LTM?

Raid

 

[Huck Finn]

I was interested to see whether the 90mm f/2.8 Contax-G Sonnar is more than just a Sonnar by name, and dug out a lens diagram. The traditional rear cemented triplet has become a cemented doublet, but it does seem to have the Sonnar arrangement otherwise. Compared to the diagram for the 1.5/50mm Opton-Sonnar...

The "traditional rear cemented triplet" was a design feature of the 50/1.5 Sonnar as your graphic shows. However, the 50/2 Sonnar had only 2 elements in the rear component. This was actually the original Sonnar design, having been developed some months before the 50/1.5. So, the 2-element rear component of the 90/2.8 for the Contax-G is a true sonnar feature.

 

[Huck Finn]

Doesn't the Nikkor 50/2 have one less rear element when compared to the Nikkor 50/1.4 ?

Roland.

Yes, it does.

 

[Huck Finn]

What has gone unmentioned in this discussion of Ernostars vs Sonnars is that as significant to the development of the Sonnar as the cemented triplet in the front was the replacement of the Ernostar's single rear element with a cememnted doublet (50/2) or triplet (50/1.5). This rear component remains as part of the design of every modern Sonnar. In this respect, they are not Ernostars.

What's in a name? Bertele's Sonnar was actually not the first lens design to use this name. The name was first applied to a Tessar-type design by the Contessa Company. After Contessa became part of Zeiss-Ikon, the Sonnar name became Zeiss's property.

Bertele developed the Ernostar for the Ernemann company. when Ernemann was taken over by Zeiss-Ikon this lens was continued in production for a few years & then dropped. It was replaced by Bertele's new Sonnar. The Sonnar name was given to the new lens not so much because it was radically different from the Ernostar, but more for business reasons. Zeiss wanted to distinguish the newly developed "Zeiss" lens from its "Ernemann" predecessor. They wanted to remove any associations with the old company from their product line. Certainly understandable as a business decision. They made the decisionback in 1931 that all lenses in this design family would henceforth be called "Sonnar." I don't know that they ever saw the Sonnar as a distinctly different lens type from the Ernostar.

I personally have no problem with the designation of "Sonnar" for the modern version of these lenses. They have more in common with the old Sonnar designs than with anything else & they perform like them. If "Sonnar" is thought of as a design "family" with variations rather than as a single design, then the name works pretty much the way that Zeiss uses it.

BTW, can anyone tell me what an "air lens" is?

 

[darkkavenger]

Max,
Is your Zeiss Sonnar in Contax mount or LTM?

Raid

both are Contax mount

 

[raid]

I have a Zeiss Sonnar 5cm/2lens in LTM which is a relatively rare lens since most such lenses were not made by Zeiss. It is either a custom made lens [which is rare] or it was made by Zeiss. Either way, it is a Sonnar.

Raid