Rolleicord Vb, Xenar 75mm/3.5 Resolution Test

[Grim Tuesday]

"Tessar formula lenses rule! Love my Minolta Autocord"

Some years ago, I had an opportunity to do a lens chart resolution test series on a number of TLRs with Tessar-type lenses. The Rolleicord Xenar optically matched the
Rolleiflex T (Tessar), both having a bit less resolution than either of the Autocords in the test. That is consistent with reputation. The Ricoh Diacord was nearly as good. The Yashinon in a like-new Yashica 124G was dismal at best.

The original poster claims his Rolleicord/Xenar is at its best near wide open. Not true for any Tessar lens. A Tessar 75mm will open to 3.5, at which it should be used as a last resort, being about 1/3 as sharp as its best. It's best is about 8.0 (and that is razor sharp) and very good to +/- one stop, things drop off fast outside that 2 - 3 stop window.

My rolleicord Xenar is as good as the original poster of this thread, although not as sharp at f3.5 as it is at f8. That would just be silly. Randy, I had similar experiences to you. My rolleicord xenar matched or exceeded my Autocord which I sold but wish I hadn't. The Yashinon I had was also disgraceful compared to the other two and I don't really understand the hype for it. Another tessar style lens I've had bad luck with was the voigtlander color-skopar.

 

[JPD]

My rolleicord Xenar is as good as the original poster of this thread, although not as sharp at f3.5 as it is at f8. That would just be silly. Randy, I had similar experiences to you. My rolleicord xenar matched or exceeded my Autocord which I sold but wish I hadn't. The Yashinon I had was also disgraceful compared to the other two and I don't really understand the hype for it. Another tessar style lens I've had bad luck with was the voigtlander color-skopar.

Yes, it's about sample variation and luck. I have had Carl Zeiss Jena Tessars that were bad performers. One Zeiss-Ikon Nettar with a 4,5/10,5 Tessar that didn't improve at all by stopping down. The focus was fine and the back lens group was screwed in all the way, so it wasn't a lens element spacing problem. The center sharpness was the same from 4,5 to 22. It was fine for those small prints people put in albums in the 1930's, but not good for enlargements.

The 3,5/75 Tessars on pre-war Rollei's and other cameras also vary in performance. Some are razor sharp, but some are just OK. The 1938 6x6 Rolleiflex on my avatar has a fine Tessar, but I also have a 1939 one with a razor sharp Tessar. The 1938 4x4 Rolleiflex also on the avatar has a very sharp 2,8/60 Tessar. Handy little camera.

The 3,5/105 Jena Tessar on my post-war Ercona is really good. I had the same luck with an Agfa Solinar 4,5/105 and Color-Skopar 3,5/105, equally sharp fine front cell focusing lenses. The 3,5/105 Voigtländer Heliar on my 1938 RF-Bessa isn't as sharp, but it's sharp enough and has other qualities I find lovely (almost 3D rendering). The 4,5/105 Heliar on my Bergheil is both razor sharp and has that "3D quality".

Lenses that are often overlooked are the dialytes on very old folding cameras. Dogmar, Isconar, Helioplan, Sytar and others. They have very even sharpness from corner to corner and are in this regard better than Tessar-type lenses, but have lower contrast and these cameras can be cumbersome to use. None of the big companies made folding or TLR cameras with coated dialytes post-war. I wish they did.

I have a 6,3/13,5 cm Goerz Dogmar on a 9x12 camera, and despite the lens being from 1916 it easily beats the decades older (I meant YOUNGER!) 4,5/135 Tessar and Skopar lenses I have tried.

 

[Paul Howell]

Yep, going back to the 40s to 70s despite very good quality control even a Rolli could roll out of the factory with a bad lens. One of the reasons the old Swiss Alpas 35mm were so good is that Alpa selected the best lens from a large number of providers, then tested each lens at the Alpa factory and took a test shot on a glass plate and tested each lens if the lens did not meet standards the lens was each taken apart and rebuilt. Computer aided design and manufacturing have greatly improved quality control.

 

[itsdoable]

.... None of the big companies made folding or TLR cameras with coated dialytes post-war. I wish they did.

The Kodak Reflex was a front cell focus TLR that had a surprisingly sharp 4 element / 4 group coated Anastar lens. The problem was that it used 620 film.

I have a 6,3/13,5 cm Goerz Dogmar on a 9x12 camera, and despite the lens being from 1916 it easily beats the decades older 4,5/135 Tessar and Skopar lenses I have tried.

I think you mean decades younger ... You know, like me, I'm decades older and sharper then the young'ins ... Not!

 

[JPD]

Yep, going back to the 40s to 70s despite very good quality control even a Rolli could roll out of the factory with a bad lens. One of the reasons the old Swiss Alpas 35mm were so good is that Alpa selected the best lens from a large number of providers, then tested each lens at the Alpa factory and took a test shot on a glass plate and tested each lens if the lens did not meet standards the lens was each taken apart and rebuilt. Computer aided design and manufacturing have greatly improved quality control.

Yes, I think most camera makers just checked the lenses with the collimator when they adjusted the focus. Franke & Heidecke (Rollei-Werke) had a white painted wall with black markings they used for testing lenses, but I don't know how often it was used and for which lenses.

The Kodak Reflex was a front cell focus TLR that had a surprisingly sharp 4 element / 4 group coated Anastar lens. The problem was that it used 620 film.

But was it a dialyte? I don't think there are any dialytes with front cell focusing.

I think you mean decades younger ... You know, like me, I'm decades older and sharper then the young'ins ... Not!

Yes, thanks, I have corrected that! I was thinking backwards.

 

[itsdoable]

...But was it a dialyte? I don't think there are any dialytes with front cell focusing....

I don't know, Ive hear it described as a Dailyte derived design, but you never know unless you are the designer.

But probably not since the stop is between the 3rd and 4th element.

 

[JPD]

I don't know, Ive hear it described as a Dailyte derived design, but you never know unless you are the designer.
View attachment 245840
But probably not since the stop is between the 3rd and 4th element.

It looks like a triplet with the front element split to allow for more corrections. Schneider did that for their 50 and 75mm 2,8 Xenars in the 1930's. The Xenar is a Tessar type, but the design is similar. They were available as front cell and unit focusing. The 2,8 Xenon on the pre-war Kodak Retinas was of this type, while the 2,0 Xenon was a double-Gauss. The five element Xenar/Xenon is sharper than the post-war four element 2,8/50 Xenar at large apertures.

https://live.staticflickr.com/5219/5471240392_e2cf8fea9e.jpg