35mm overview DSC00439

During the nexte weeks I will test a large amount of vintage Minolta/Canon/Nikon lenses and new Sony lenses on the Sony A7/A7R. To prepare these tests I have played with several selected lenses during the last week. A few of the results are shown here and in two other articles.


All of these test results are preliminary.


All images shown in these three articles are JPGs directly out of the A7 / A7R / A900.

No postprocessing (apart from cropping) was applied.

The original 2.8/35mm Biogon (1936) from Ludwig Bertele is the prototype of all later 2.8/35mm lenses. It was generally considered the best and fastest wide-angle of its time. In this test I've compared three vintage Minolta lenses (Minolta MC 1.8/35mm from 1973, Minolta MD 2.8/35mm from 1981, and Minolta MD 3.5/35-70mm from 1981) along with two recent Zeiss lenses (Zeiss ZM 2.8/35mm from 2008 and Sony Zeiss ZA 2.8/16-35mm from 2009). All MF lenses were tested using the 24MP Sony A7. Since Sony Switzerland doesn't deliver the Full Frame LA EA3 adaptor (without translucent mirror), the ZA 2.8/16-35mm was tested using the 24 MP Sony A900.


Thanks to Matthias Sommer for lending me his brand new A7!



artaphot A7 MC 35mm f18 Domodossola

The Minolta MC W.Rokkor-HH 35mm 1:1.8 always had an excellent reputation. Introduced 1968 at the Photokina in Köln, it soon became known as "the best wide angle ever". The MC 1.8/35mm was part of a series of high-performance lenses (others were the MC 2.8/21mm, 2.5/28mm, 1.2/58mm, and 1.7/85mm), and it was the fastest 35mm lens of its time. It was surpassed only half a decade later when the legendary Nikkor 1.4/35mm appeared (using radioactive thorium glass). 

The MC 1.8/35mm is exquisitely manufactured - even after 40 years it focuses as smooth and silky as any conteporary Leica lens. Its barrel is manufactured from brass and aluminium, and due to its Leica-patented black chroming most lenses look "like new" even after 40 years. The combination of these metals however is quite heavy - the MC 1.8/35mm comes at 415g.

At f1.8 the Minolta MC 1.8/35mm has some LoCAs, and there's quite a bit of coma, but the overall image rendition is very balanced and pleasing. The contrast is rather low (usually an advantage in low light situations), and its corner resolution at f1.8 is much better than the Zeiss ZM 2.8/35mm (2008) at f11!

At f2.8 (not shown here!) the LoCAs are gone, but coma remains. Overall image quality is similar to  f1.8.

At f5.6 coma is almost gone, and at f11 the image quality is outstanding, even in the extreme corners. CAs are negligable.

Distortion - always a problem on retrofocus wideangles - is negligible, and (surprisingly!) even better corrected than on the Zeiss ZM 2.8/35.

The MC 1.8/35mm certainly is a lens capable of future 50MP sensors.


artaphot A7 ZM 35mm f28 Domodossola

The Zeiss Biogon ZM 2.8/35mm is a beautifully crafted lens, manufactured by Cosina in Japan. The lens is very small and thus fits nicely to the A7/A7R - but its optical performance is simply not sufficient for the 24MP sensor of the A7. I certainly was surprised to see such a low image quality in the corners, but owners of the lens confirmed that these problems are "real" (which means that the ZM 2.8/35mm tested here seems not to be defective). I certainly will get in touch with Zeiss to check if the corner problems of the ZM 2.8/35mm are inherent to the lens or simply related to the sensor configuration of the A7. For time being I suspect that the lens itself causes the problems, and not the A7 sensor. 

At f2.8 the image quality is quite disappointing. There is some quite pronounced astigmatism - not only in the corners, but also in the field. The CAs are disturbing, and distortion isn't corrected as good as in the much older retrofocus Minolta MC 1.8/35mm.

At f5.6 the image quality doesn't get much better. The problems in the field remain obvious (not shown here).

At f11 there are still quite a lot of problems - in fact, for printing I certainly would prefer the f1.8 image of the Minolta MC 1.8/35mm over the ZM at f11!

Since the ZM is really beautifully machined and exceptionally small, I would recommend it on the A7 mainly for reportage and street photography. Landscape or architectural photographers will be much more happy with a used Minolta MD 2.8/35mm that comes at 20$ / EUR. See below for details...  


artaphot A7 ZA 16-35mm f28 at35mm Domodossola

The Sony Zeiss ZA 2.8/16-35mm is known to have its weakest spot at f=35mm, while being excellent at f=16mm. In my opinion this is a reasonable compromise. From earlier tests we know, that the ZA 16-35mm also at f=35mm becomes excellent when stopped down. At f11 the ZA 16-35mm has a better detail resolution and less CAs than the Minolta AF 2/35mm or the Sony AL 1.4/35mm G lenses. The missing detail resolution at f2.8 comes mainly from remaining field curvature, and thus is of little significance in real-world reportage shootings at f2.8.


35mm overview DSC00652

Intrigued by the results of the MC 1.8/35mm vs Zeiss ZM 2.8/35mm shooting I made another quick test on the following morning, just before returning the A7 to its owner. The ZM 2.8/35mm was re-run, as a reference, on a different location (the station of Domodossola in the Italian Alps). In addition I had the dirty cheap Minolta MD 2.8/35mm in its last MD-III variant and the equally inexpensive Minolta zoom MD 3.5/35-70mm with me.


The lenses were manually focused to the same level as the window shown in the corner crops, using the 11x magnification of the A7 life view.














artaphot A7 ZM 35mm f28 Domodossola 2

As above, the ZM 2.8/35mm doesn't shine. The center resolution ist excellent, but the filterpack of the Sony A7 causes lots of problems with corner resolution. The Leica M is much better suitable for this kind of wideangles. 


Minolta 35mm f28 MD-III on Sony A7

The Minolta MD 35mm 1:2.8 in its MD-III incarnation is a small and lightweight lens from 1981 -  a mere 180g... Its lens barrel is manufactured solely from aluminium (and not from ideal combination of "brass on aluminium"). The focusing thus is not as smooth any more as with comparable MC lenses, and the aperture ring is made from plastics. Apart from this the lens feels solid, focusing is precise and not as steep as with contemporary AF lenses.

The lens performs remarkably well even at f2.8 - we have a very good detail resolution over the entire field and in the Full Frame corners, and very little CAs. At f2.8 there is visible vignetting. Being in a hurry, I haven't checked for distortion. At f5.6 the vignetting is gone, the contrast has increased, and the lens now can be used perfectly for critical landscape work. At f11 there's again a slight improvement in the corners, and a slight decrease of resolution in the center (diffraction).

This lens as well waits for future 50 MP full frame sensors ...


artaphot A7 MD-III 35-70mm f35 Domodossola

This Minolta MD 35-70mm 1:3.5 (also in the MD-III variant) is a sample from the second generation of the 3.5/35-70mm. The first generation (MD-II) obviously had a slightly different optical construction and a visibly worse performance, while the third generation of the MD 3.5/35-70mm includes a macro mechanism.

Zooms usually have corner issues at their shortest focal length, and resolution problems at their longest focal length (the Sony Zeiss ZA 2.8/16-35mm being a remarkable exception). Therefore we would expect some corner problems, and in fact the performance of the 3.5/35-70mm is not as outstanding any more as it was on 16 MP APS-C. Nevertheless the cheap Minolta 3.5/35-70mm performs visibly better than the Zeiss ZM Biogon 2.8/35mm.


And what about the brand new Sony Zeiss Biogon FE 2.8/35mm? I recently talked to the responsible product manager at Sony Switzerland, and she was less than enthusiastic about lending me their new Biogon - even though Sony Japan provides them with samples, and even though my name and e-mail adress still is printed in the most recent "Sony Fotospiegel": "For Professional Lens Support: Contact Stephan Kölliker at ...".

Times have changed, and there's now certainly less enthusiam at Sony Switzerland Digital Imaging than it was four years ago ... the reliable partners I used to have there have moved on: To Samsung, to Canon and elsewhere.