Rolleiflex Lenses - Barrel Distortion?

[Andre Noble]

Anyone familiar with Rolleiflex Lenses & Barrel Distortion can comment on whether there is barrel distortion in images produced by the TLR Rolleiflex lenses? Are the 80mm and 75mm lens of a retrofocus designs (means likely barrel distortion) or are they of some other design.

The shortest non-rangefinder lens for medium format that I have experienced without distortion is the 127mm Mamiya RB/RZ lens. There is even slight (but noticeable if you look closely) barrel distortion on the Gauss design RZ 110mm lens. But on te RZ/RB definitely on 90mm and below lenses.

 

[Andre Noble]

Thanks for taking time to post that. Looks promising, but in reality one really needs to see how straight lines (known to be straight - can't be too sure of that with old wooden house) running across the entire frame are acting at the periphery of the image.

PS, I know some people could care less about a few percentages of barrel distortion, but it's something I am very sensitive to...

 

[Dan Daniel]

I've seen it in a 75mm Xenar and a 75mm Xenotar. Haven't noticed it in an 80mm Xenotar. Haven't shot enough with a Tessar or Planar to say. Very very slight in all cases. Here's probably the most extreme I've seen, Xenar on a Rolleicord Va(2)-

 

[piu58]

You have to take into account your enlarging lens too. Mots often its is a Tessar type, and if of less quality in comparision to a Flex Planar.

 

[Aron]

I can't give you a definitive answer, but I can tell you this subject is rather complex and we can't state that retrofocus means (barrel) distorsion, while non-retrofocus means ruler-straight flagpoles at the edge of a one square meter print.

If you take a look at the diagram of the 3,5/75 Rolleiflex Planar, it looks rather similar to the 3,5/100 Hasselblad one and with the latter distorsion is slightly less than -0,1 % at infinity, however, the different focal length will change the distorsion figure, ceteris paribus. Take a look at any of the Schneider datasheets that show this clearly. Distorsion figures also depend on magnification factor (at both taking and enlarging). My Jupiter-3 1,5/50, a Sonnar copy is not retrofocal, yet it shows noticable pincushion distorsion up close.

If you take a look at the ZM 2/50 Planar, the 2,5/50 Summarit and 2/50 Summicron, not the same designs, but closely related, the Zeiss has roughly -1.5 %, the Summarit 1 %, while the Summicron aroung 0,25 % distorsion at infinity. While the 2,8/28 Elmarit ASPH is retrofocal, it has somewhat lower distorsion, than the C Biogon 2,8/35.

I would expect the higher end Rolleiflex lenses to have lower distorsion figures than my Xenar (because of more symmetrical design). Straight lines don't always stay so with my Rolleicord (with Xenar), but this is noticable much more with a ruler than to my naked eye, even on large prints. I was seriously worried about it for a week one time, than got over it. If you want low distorsion, cheap, I would suggest you find a camera with the two-element Rodenstock Periscope, but treat f/16 as its working aperture.

If money is no object, try to find a 60 mm Biogon equiped camera, until than the best choice would be to try a Rolleiflex and see if it's good enough for you.

 

[Steve Smith]

I know some people could care less about a few percentages of barrel distortion

And others couldn't care less.

but it's something I am very sensitive to

As am I to that!!


Steve

 

[Andre Noble]

Aron, I have the Zeiss ZM Biogon 35 f2. almost Zero distortion. It's a pleasure to work with for that reason. Straight lines are beautiful.

 

[TheFlyingCamera]

From legend, one of the most distortionless lenses ever made is the Hasselblad Superwide Biogon 38mm f4.5. But it's a scale focus, fixed lens camera on a custom body.

Relating to the Rolleiflexes, in general, the Planar lens design has very low distortion (thus the name). If you want one, spend the extra money for one of the f2.8 Planar lens versions. I love mine. I haven't noticed significant barrel distortion, but I haven't been looking for it either.

 

[Aron]

From legend, one of the most distortionless lenses ever made is the Hasselblad Superwide Biogon 38mm f4.5. But it's a scale focus, fixed lens camera on a custom body.

Relating to the Rolleiflexes, in general, the Planar lens design has very low distortion (thus the name). If you want one, spend the extra money for one of the f2.8 Planar lens versions. I love mine. I haven't noticed significant barrel distortion, but I haven't been looking for it either.

Actually, the name for the famous Zeiss design that was copied by nearly every lens maker who wanted sharp lenses with wide apertures, came from the fact that it's field was flat, in other words planar, not that it had very low distorsion. It's only a bonus that comes with certain double-gauss lenses, that their distorsion figures are also low.

The SWC's (and Alpa's and few aerial camera's) Biogon does have very low distorsion, roughly -0,2%, but the 5,6/60 Biogon's (for NASA) is 1/100 th that of its 4,5/38 brother. Not that this matters anything is actual, non-techno-fetishist photography.