Medium Format Lenses with the Pentacon Six Mount
A comparative test
by TRA

The wide angle lenses (3)

[C373-0A] The wide-angle lenses, from L to R: 40mm Distagon, 50mm Flektogon, 40mm Curtagon,
65mm Flektogon, 45mm Mir 26, 65mm Mir, 60mm Curtagon


Since completing the original tests in Hitchin Town Square I have been able to test the 55mm Arsat shift lens.  Like most shift lenses, this has a pre-set (non-automatic) aperture.  Initial results indicate that this is an outstandingly good lens.  Details of the results of my tests can be seen here (scroll down to bottom of page).


Wow! At f/11 the Schneider Curtagon is sharp and high in contrast! But at f/3.5 it is no match for the 50mm Flektogon at full aperture. It is less sharp and less contrasty than the Flektogon at f/4.

At f/11 sharpness increases considerably.

[C296-3: 60mm Curtagon at f/11]


The 65mm Mir 38B is superbly sharp and contrasty into the corners at f/11 – at least as good as the 60mm Curtagon, possibly a hint better than it, although the difference is so slight that it could be down to the lab. The 50mm Flektogon beats it by the tiniest fraction, as revealed by the definition and contrast of the “No Exit” sign near the left-hand edge of the image. At f/3.5, the reduction in definition is very slight. This truly is an excellent result that the scan has not done justice to.  Remember that at full aperture the cobblestones near the camera are beyond the limits of the depth of field, and will therefore be out of focus.  This is a fact of optical life, not a lens fault.

[C296-10: 65mm Mir 38B at f/3.5]

[C296-9: 65mm Mir 38B at f/11]

The aperture on my 65mm Mir (an eBay purchase!) does not always stop down beyond f/11 when I rotate the aperture ring. My repairman has looked at it, and was shocked at the poor quality of some of the machining. It generally does now (in 2002) stop down properly with the added impetus that comes when the shutter is released and it is moving fast from full aperture to the selected value.

It might be better to use a 65mm Carl Zeiss Jena Flektogon. But production of this f/2.8 lens stopped towards the end of the 1960s, as far as I can determine, and it is in consequence relatively rare.

However, the ancient 65mm f/2.8 Flektogon illustrated on the right reveals a smoothness of operation that my 1992 Mir 38B doesn’t come near to: movement of aperture ring, focussing, diaphragm stop-down pinall are far superior to the Arsenal product.

The 65mm Flektogon was no doubt produced in various finishes.  (See the page on lens cosmetic finishes here.)  However, the last style in which it was produced appears to have been the so-called “Zebra” style, and an example of this lens in that style can be seen on the page given in the above link.  The lens illustrated there was produced in May 1967, and the 65mm Flektogon appears to have been manufactured for the last time in February 1969, the highest serial number for it being 8,415,309 – unless a visitor to this website has one with a higher serial number, of course!

That was before multi-coating was introduced by Carl Zeiss Jena, starting in 1976, in consequence of which all 65mm Flektogons will be single-coated (unless multi-coating has subsequently been added by another company, which is not impossible but is extremely unlikely).

[C308-32: On the left: a 65mm f/2.8 Carl Zeiss Jena Flektogon produced in December 1965.
On the right for comparison: the 65mm f/3.5 Arsenal Mir 38B]

Identical shots that I have made at f/11 using the above Mir-38B and the 65mm Flektogon illustrated beside it have produced images that were indistinguishable in 8"×8" (200mm×200mm) prints.

An image taken with a "zebra" 65mm Flektogon can be seen here, at the bottom of that page.
Mir Construction Quality

However, while sitting quietly in its case, the 65mm Mir decided to stop operating its aperture at all, so that then it only worked at f/3.5!  I had to send it off for repair, and was glad that I had bought the Carl Zeiss, which was still silky smooth, reliable and faultless.

March 2006:  I recently sent the Mir 38B 65mm lens to Foto-Service Olbrich in Görlitz, Germany.  There, Herr Peter Olbrich confirmed that although “Russian” (in this case, Ukrainian) lenses are often optically excellent, mechanically they are very poor.  This lens was no exception, and contained broken screws and broken screw threads.  He carried out the best-possible repair – and to my eyes the lens now seems to operate perfectly – but he complains of considerable play in the aperture control, a consequence of the way it was constructed.  To see the contact details for Foto-Service Olbrich, click here.

Kevin Ing found his 65mm Flektogon “definitely much sharper than the 65mm Mir”.  See his “Kievaholic” website here.  In his very rigorous tests, some of his results were quite different from mine.  As he said to me in an e-mail, “Perhaps it really depends a lot on sample variation and what has happened to these lenses since they were manufactured.”  With a second-hand lens, one never knows when it has been disassembled, cleaned and then incorrectly re-assembled by a well-meaning DIY repairer.

The dimensions of the 65mm Flektogon are almost identical to those of the 50mm Flektogon, although it weighs considerably less.


In conclusion: the 50mm Carl Zeiss Jena Flektogon and the 65mm Arsenal Mir are very sharp – at least as sharp as the 60mm Schneider Curtagon – and at maximum aperture, the 50mm Flektogon beats the Curtagon! The 45mm Arsenal Mir-26B is, however, much less sharp and contrasty.

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© TRA January 2002.  Latest revision: July 2015