Super Angulon vs. Biogon at higher magnifications

[genotypewriter]

Hi everyone,

Keeping aside any differences between lenses using even the same design and assuming common apertures, generally speaking, would one design show fewer aberrations than the other at higher magnifications?

Specific aberrations I'm interested in minimizing, starting from most annoying first: longitudinal CA, lateral CA, field curvature, ones causing general off-axis softness.

Thanks a bunch in advance!

[Dan Fromm]

Hmm. Where's the Super Angulon equivalent of the 40/5.6 S-Biogon?

The f/4.5 Biogons that made it to market are all 90 degree lenses. 38 mm, 45 mm (100 made), 53 mm, 60 mm (a handful of these have escaped from NASA) and 75 mm. The 53/4 SA's claimed coverage is 95 degrees, all other SAs' claimed coverage is ~ 105 degrees. The 53ers (Biogon and SA) cover 2x3. The only f/4.5 Biogon that covers 4x5 is the 75er.

Save up your small monetary units and buy a 53/4.5 Biogon and a 53/4 SA and test them at the magnifications of interest to you. Or get a 75/4.5 Biogon and an f/5.6 or f/8 SA and test. For other focal lengths that cover 4x5 or larger your question is completely empty.

Yes, I know that coverage grows with magnification.

More seriously, what decision do you want to base on the information your question elicits? I ask because it is possible that what you're trying to accomplish can be done well enough with another lens.

[genotypewriter]

Thanks for the reply, Dan. The question was more about the general designs than exact implementations. I.e. keeping aside availability under various formats, is it possible to draw any generalised conclusions about the close distance performance of these two designs if focal lengths, apertures, max common format size, magnification, etc. were identical?

My guess is that the SA being a less tubular design, it might perform better? Correct me if I'm wrong.

Thanks again.
Guy

[richardman]

Aren't most Biogon "collector's items" due to the scarcity? If they are unobtainable without big $$$, that might make their technical prowess, if any, sort of moot, to most people.

[Emmanuel BIGLER]

Hello from the other side of the planet!

The Zeiss Biogon, Schneider Super Angulon and Rodenstock Grandagon belong to the same family of "modern" wide-angle view camera lenses sharing in common two strong negative meniscii as their first and last lens elements.
This is a major change with respect to pre-WW-II LF wide-angle lenses like the not-super-Angulon (positive lens elements on entrance and exit of the lens).

If we set aside Roosinov's 1946 patent, we can say that the prototype of those modern lens designs is the Wild Aviogon developed just after WW-II by Ludwig Bertele for Wild in Switzerland.
Biogons, Super Angulons and Grandagons share the same quasi-symmetric design, hence are supposed to perform quite well a shorter distances, due to their symmetry (in opposition to retrofocus asymmetric designs).

Schneider and Rodenstock pushed this kind of lens up to 120° of angle whereas Biogon lenses, at least those actually available to the amateur (even at very high collector's prices) is more a 90° - 95° design.

Even if you cannot read Italian (admittedly, a Frenchman can understand most of the contents), the most interesting article on Biogon lenses has probably been written by Marco Cavina and features FTM curves for the 75 mm Biogon and some drawings relative to 120° Aviogon and Biogon prototypes.
You can compare the FTM curves and distorsion curves of the 75 mm Biogon to its German competitors, but the data given by Marco Cavina are probably given for long distances and do not supply any useful information regarding short working distances. And the very strong separation between sagittal and tangential FTM curves of the 75 mm Biogon makes the diagram very dfficult to understand!

http://www.marcocavina.com/articoli_fotografici/Hypergon_Topogon_Biogon_Hologon/00_pag.htm

The article proves that the Biogon design is not intrinsically limited to 90-95°: simply Zeiss at a certain period (the beginning of the sixties ?) decided to leave the LF lens market to its competitors in Bad-Kreuznach and Munich, and did not push forward other Biogon types over 100° of angle for general-purpose LF photography.

Yes there is the famous 110° Hologon design by Erhard Glatzel (who designed the S-Biogon mentioned by Dan), but it is a totally different kind of lens.
Again read more about Hologons in Marco Cavina's article, at the end of the (long) web page pointed above.

[ruilourosa]

buy a G-claron and be happy!

super Angulon´s, grandagons, nikkor SW, and Angulon´s are OK when used at a portrait lenght, but if you want super sharpness (high micro contrast usually related to macro lenses) you should go to a macro design

cheers

[genotypewriter]

Thanks for the detailed reply, Emmanuel. You have a good point about the coverage as well as Hologons.

Anyone have an idea about how a SA compares to a Biogon w.r.t. the aberrations I mentioned in the top post.

Thanks again.

[Dan Fromm]

Guy, I have and use a 38/4.5 Biogon and a 47/5.6 SA. I don't use either closeup.

I've read that the 38/4.5 Biogon (same lens as mine, different shutter and mount) on Hasselblad SWx cameras is very good at its close focusing limit. I have no idea how close it focuses on an SWx or how good "very good" is. I've taken a few shots with mine at ~ 1' film-to-subject distance, wasn't impressed with the results but since there were only a few shots and I'm me operator error is very possible.

At "normal" distances both lenses are more than sharp enough, CA isn't noticeable, blah blah blah. I say blah blah blah because the aberrations you asked about are all sensitive to relative aperture. I rarely shoot near wide open, have no idea what your intended application requires.

I say intended application because if you're just asking a vague general question you probably have hairy palms.

[Drew Wiley]

You need to be more specific. I know of only one relatively modern Biogon intended for 4x5 use, a big clunker with a limited image circle, but with less distortion than
the Super-Angulon and its numerous clones. I've used certain wide-angle lenses relatively close to things with acceptable results; but they sure wouldn't be my first choice for that kind of work. Lenses like G-Clarons, Fuji A's, and even some general purpose plasmats will do a better job. I don't understand why you want to take that path.

[Emmanuel BIGLER]

The feeling I have is that special biogons like the 40 mm S-biogon were only developed to meet a very specific demand from the industry: making high performance "optical" copying work with short objet-to-film distances and very high specifications in terms of sharpness and distorsion.

This is probably well achieved in the 40-mm S-biogon, a lens which, according to some of the happy owners, are hard to mount on an enlanger due to their very short distance between the last lens vertex and the focal plane.

If you only need to copy flat objects, you do not need a wide-angle lens except if you have some hard "mechanical" constraints in terms of object-to-lens distances.
Hence the reference to regular copying lenses as mentioned above is, IMHO, THE proper answer to the problem!

Large format wide-angle lenses were developed for other purposes, e.g. landscape, architecture and (relatively) far-distant objects. Hence there is no real reason to add another design constraint, i.e. that the lens not only should provide outstanding image quality up to 105° of field angle, but that this level of performance should be maintained down to the 1:1 ratio!

Moreover, by purposedly choosing a LF WA lens for copying work, you'll have to live with the "natural vignetting" which is intrinsic to all quasi-symmetric lenses.

I remember a discussion on the French LF forum where I (quietly, as usual ;) ) mentioned the Zeiss-official illumination curves for one of the legendary Biogons (the 38 mm, hence definitely off-limits here): at 45° off-axis (90° of total image field), the loss in terms of illumination w/respect to the optical axis is between 1 and 1.5 f-stops. Immediately one of the forum readers, a real-life professional practitioner of the Biogon, protested that there was no vignetting with a 38 mm Biogon.
My argumentation was: this is not my opinion, this is Zeiss official specs ;)

[Jac@stafford.net]

You need to be more specific. I know of only one relatively modern Biogon intended for 4x5 use, a big clunker with a limited image circle, but with less distortion than
the Super-Angulon[...].

There was the Pacific Optical 3" Biogon which had a rear lens larger than 4" in diameter and sat very close to the film plane with the outcome that there was very little fall-off on 4x5. I am pretty sure it was designed to be used over 5" rollfilm. I can post images of one machined to fit a #5 shutter.

[Peter Yeti]

I'm not exactly sure what you're after, but once I tried to use my SA 5.6/90mm XL for close-up work around 1:1 and the result was disastrous. The resolution was very poor and it seems clear to me that the design of the lens was not made for this kind of work. But beyond 1:10 it's an excellent lens with high resolution and very small distortion.

One of my most favourite cameras ever is my Hasselblad superwide with the 4.5/38mm biogon, sorry that I don't have a LF biogon. The shortest focussing distance is about 30 cm (~12"), giving 1:5. But I've never shot at this ratio because the camera is simply not meant for this. At longer distances, the 4.5/38mm biogon is perhaps the most outstanding wide angle I've ever seen. But it's restricted to 90° image angle and my feeling is that the SA would perform nearly as well within this image angle. The fall-off isn't bad enough to be really disturbing me and to the best of my knowledge there isn't a centre filter available. Without movements, the 90mm SA XL might be used on 4x5" without centre filter with similar results regarding fall-off. But once movements are used one certainly might want one if even lighting is desired.

Long story short, my biogon and SA's seem very similar but the biogon might be optimized a bit further regarding resolution because no compromises for a larger image angle had to be made.

[Jac@stafford.net]

At longer distances, the 4.5/38mm biogon is perhaps the most outstanding wide angle I've ever seen.

120002

[Arne Croell]

Long story short, my biogon and SA's seem very similar but the biogon might be optimized a bit further regarding resolution because no compromises for a larger image angle had to be made.

Plus, one has to take into account the aperture used: Biogons, including the 75mm one, were designed to be used with very good results wide open (at the expense of coverage), whereas the open aperture on a Super-Angulon (5.6 or 8), although usable in the center in a pinch, was intended only for focusing. So wide open the SA will surely be worse, stopped down it probably depends.

[Peter Yeti]

That is probably true. At least I can confirm that the biogon performs very well wide open. I shot tons of night city scapes free hand with the biogon wide open and they are tack sharp. I think I've never used an SA wide open, so I can't compare. And the SA's image angle of 105° refers to f22 (like usual), at smaller f-numbers it's less of course.

[Jac@stafford.net]

FWIW, lenses for aerial mapping were rated at maximum (wide open) aperture. Lower altitude tasks made Biogons' reputation.