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

240-300mm


To achieve these focal lengths in my original tests in 2002 I used these lenses:
120mm Biometar plus Panagor 2× converter
250mm f/3.5 Arsenal Jupiter-36B
250mm f/5.6 Joseph Schneider MC Tele-Xenar
250mm f/5.6 Carl Zeiss Oberkochen Sonnar in Hasselblad mount
140-280mm f/5.6 Joseph Schneider MC Variogon at 280mm
300mm f/4 Carl Zeiss Jena MC Sonnar
150mm f/2.8 Arsenal Kaleinar + 2× converter
A further possible combination is the 150mm f/4 Joseph Schneider MC Tele-Xenar + 2× converter

In 2019 the results of tests with the 240mm Novoflex Noflexar lens were added.

240-250mm


[C373-6A: 240-250mm
From left to right: 120mm Biometar plus Panagor 2× converter, 250mm f/5.6 Joseph Schneider MC Tele-Xenar, 250mm f/3.5 Arsenal Jupiter-36B, 250mm f/5.6 Arsat (formerly called “Telear”)
and 250mm f/5.6 Carl Zeiss Oberkochen Sonnar in Hasselblad mount]
(The 240mm Noflexar can be seen here.)

240mm

120mm Biometar + Panagor 2× converter

Well, if I had seen the results obtained with the Panagor 2× converter and the 80mm lens before taking these shots, I would have used the Arsenal converter instead.  As with the standard lens, the Panagor produces images of a remarkable softness with the 120mm Biometar.  This combination is just not usable at full aperture.  With f/11 set on the Biometar, this combination yields images of acceptable sharpness across most of the frame.  If we are interested in 2× 120mm, the “Russian” (strictly-speaking, Ukrainian) converter is clearly the one to try out.

To be fair to Panagor, they do advise against using maximum aperture on any lens that is used with this converter.
  

 [C298-3: 120mm Biometar at maximum aperture (f/2.8) + Panagor 2× converter
I hope that even on a computer screen the appalling softness of this combination will be visible.  Compare it with the shot taken with the 180mm Sonnar.]
240mm Novoflex Noflexar


This pistol-grip lens is designed for speedy use hand-held.  As the aperture is totally manual, it is also designed to give good resolution at maximum aperture.  Just squeeze the lens to focus, and fire the shutter.  See the overview of the Novoflex lenses for the Pentacon Six, starting here.  However, as I wanted to test a range of apertures, and to minimise differences in framing between one image and another, so I mounted the lens on a tripod for these tests.  I went back to the Market Square in Hitchin.  We can see that the ownership of the Tea & Coffee House has changed hands.  It may be that the building has been repainted since the original shots 16 or 17 years earlier, or perhaps the prints from which I scanned the test results in 2001 and 2002 were slightly pink.  For these Novoflex tests, I have scanned from the negatives.

All of these 240mm Noflexar images were shot on a Pentacon Six with Fuji PRO160NS film in September 2018.

At maximum aperture: f/5.6 (1/250 sec)
[Nov_240_f5pt6.jpg (C562-17)]
One stop down: f/8 (1/125 sec)
[Nov_240_f8.jpg (C563_1-2)]
Two stops down: f/11 (1/125 sec)
[Nov_240_f11.jpg (C562_14-15)]

Three stops down: f/16 (1/60 sec)
This is a slow speed for a lens of this focal length, which is why I used a tripod.  The lens also stops down to f/22, but I decided that in most circumstances users were unlikely to stop down the lens that far.
[Nov_240_f16.jpg (C562-16)] 		We note a tiny amount of vignetting, which in these images is more obvious in the top left-hand corner.  The vignetting appears to become sharper, but not larger, as the lens is stopped down.

To the right we see a greatly-enlarged detail from near the left-hand edge of the image shot at maximum aperture.  The results are excellent, and definitely justify the manufacturer’s claim that this lens can be confidently used at maximum aperture.  Even with the relatively slow-speed film used here, the late British summer sunshine with a small amount of hazy cloud permitted a shutter speed of 1/250 second at maximum aperture.  This speed can easily deliver sharp images when the camera is hand-held.
Detail at maximum aperture, f/5.6
[Nov_240_f5pt6L.jpg (C562-17, cropped)]

250mm lenses

Now to the 250mm prime lenses.  The Schneider Tele-Xenar is sharper than the Carl Zeiss Oberkochen Sonnar, and both of these lenses are sharper than the Arsenal Jupiter.  Now to the detail.  At its maximum aperture of f/5.6, the Tele-Xenar is clearly much sharper across the whole of the frame than the CZO Sonnar.

As with the 150mm lenses, the maximum aperture of the Schneider lens is much smaller than that of the Arsenal 250mm lens we are testing here.  The 250mm Tele-Xenar is an f/5.6 lens, whereas the 250mm Jupiter boasts a maximum aperture of f/3.5! There could well be low-light situations where you would not even get a steady hand-held shot with the Tele-Xenar, but would with the Jupiter. And the Jupiter gives you a viewfinder image that is about three times as bright as the Tele-Xenar, whatever the aperture you are using.  Of course, with the Arsenal lenses, you are carrying a LOT more weight around, AND you need to spend MUCH more for filters.  But at its maximum aperture of f/3.5, the Jupiter is SOFT across the whole of the frame.  Use this aperture to help you focus, NOT to take pictures.

Let’s be fair to the lens and stop it down to f/5.6 to compare it with the other two.  It still comes in a poor third, both as regards sharpness and contrast.

How do they perform at f/11?  Well, frankly, the same.  The Tele-Xenar is considerably ahead of the Carl Zeiss Oberkochen Sonnar in both contrast and sharpness, and the Sonnar is slightly more contrasty than the Jupiter, although as regards sharpness the difference is marginal.  This 1980 version of the Jupiter is not multi-coated, and it has copper-coloured aperture blades.  I don’t know if this negatively affects contrast, but have read that the copper aperture blades and the copper/bronze metal shutter curtains on the older “Hasselblad clones” had an anti-reflection coating.

On the plus side, a 250mm f/3.5 Jupiter with a 2× converter gives you a very useable 500mm f/7 lens, whereas a 250mm f/5.6 Tele-Xenar with a 2× converter gives you a much dimmer 500mm f/11 lens – especially if you are using the standard viewfinder screen in a Pentacon Six or Exakta 66. (A Rollei screen in either of these cameras will slightly more than double the viewfinder brightness, and a Kiev 60 TTL prism used via an adapter from www.baierfoto.de in Germany will double the brightness again.)

[C298-4/5: 250mm Tele-Xenar at f/11  1/125 sec]
 

Lists of lenses from the Arsenal factory in Kiev have over the years referred to two – or sometimes three – 250mm lenses: the f/3.5 Jupiter, the f/5.6 Telear and the f/3.5 Telear.

I have always doubted that an f/3.5  Telear existed – on the basis of the other data provided (weight, filter size).  In any case, what would be the point of having two f/3.5 250mm lenses for the same system?  (OK, logic is not always part of the answer!)

In any case, my Telear lens (now re-branded Arsat) contains the new name ring, but it still states that it is a “1:3.5” lens – even though the aperture ring shows that the maximum aperture is f/5.6!  So the error seems to have originated in the manufacturing department a long time ago and to have been perpetuated not only in some literature, but even in the machining of the new name ring.

 Notice that on the Jupiter (on the left) the aperture ring rotates in one direction; on the Telear (Arsat) it rotates in the opposite direction – a poor design feature, as after a while using a particular lens one automatically knows in which direction to rotate the aperture ring to open up by one stop, for instance.

The Jupiter is a heavy lens, but lacks a tripod socket.  Mounting the camera on a tripod using the camera’s tripod socket is not ideal, as the heavy lens moves the centre of gravity much further forward.  A suitable support for such lenses can be seen here.
All Joseph Schneider Exakta 66 lenses rotate in the same direction as the Jupiter – i.e., with the largest aperture at the left, as one looks at the lens from above the camera (as in this photo).
All Carl Zeiss Jena Pentacon Six lenses rotate in the same direction as the Telear – i.e., with the largest aperture on the right, as one looks at the lens from above the camera.

Needless to say, the “Telear”/Arsat 250mm f/5.6 is a lot lighter than the Jupiter.  It also yields excellent results.
 

This is what you get if you tilt a wide-angle lens upwards: keystoning (converging verticals)!  Here I clearly needed a shift lens.  However, I include this shot, un-cropped and un-corrected, to give a comparison of the angle of view between the 45mm Mir-26B, used here, and the 250mm “Telear”/Arsat (illustrated above), on the right.
[C342-10] Mir-26B 45mm f/3.5 lens
[C342-12] “Telear”/Arsat 250mm f/5.6 lens
Both with Fuji NPS 160 ISO film on my Pentacon Six, 1/250 f/16  Friedrichshafen, southern Germany.

Kevin Ing found his 250mm f/5.6 Arsat (the “Telear” lens) sharper than the Jupiter 250mm f/3.5 lens.  See his “Kievaholic” website here.  (Note also  – in the Wide-angle section – his and my comments on sample variation and the uncertain history of older lenses.)

280mm

At its longest reach, the larger Variogon lens attains 280mm.  At its maximum aperture of f/5.6, it yields an image very close to the 250mm Tele-Xenar lens at its maximum aperture (also f/5.6).  Only with the loupe can I see that the lettering of the shop name is not quite as sharp.  A greater difference is caused by the variation in print density introduced by our friends at the lab!  At f/11 it remains fractionally behind the prime lens in sharpness – but you’ll need a powerful loupe on a large print to see it!

[C303-7: 140-280mm Variogon at 280mm: f/11 at 1/60]

300mm



[C308-7: From left to right: 150mm Arsenal Kaleinar plus Arsenal 2× converter, 140-280mm Schneider Variogon at 280mm, and 300mm f/4 Carl Zeiss Jena Sonnar]


As we use longer and longer focal length lenses on the same subject, the area of sky in the image diminishes, and eventually disappears.  Although correct use of the meter prevents any exposure problem, most labs – even so-called “professional” ones – are not quite up to this, so their integrated reading shows a negative with less dense areas (less sky), and they print lighter to compensate.  They have done this with the shots taken with the 300mm Carl Zeiss Jena Sonnar, making comparisons harder.  However, in spite of this, we shall try to compare the prints.

At its maximum aperture of f/4, this lens produces an image that is satisfactorily sharp across the whole of the frame.  However, inspection with the loupe reveals that it is not quite as sharp as the Schneider 250mm Tele-Xenar at f/5.6 – not really a fair comparison.  At f/5.6 I would expect this lens to match the Tele-Xenar.  At f/11 it appears just as sharp as the Tele-Xenar at the same aperture – and this was the top-performing 250mm lens in our head-on test described above.
So how does the 300mm Sonnar compare with Schneider’s 140-280mm Variogon at 280mm?  Given the results of the comparison between the Variogon and the 250mm Tele-Xenar above, it should not surprise us to see the same here.  The Variogon is the tiniest fraction behind the Tele-Xenar, and at f/4 the Sonnar is a tiny fraction behind the Variogon at f/5.6.  At f/11 with the aid of the loupe I can see marginally more detail in some parts of the image taken with the Variogon than in the image taken with the 300mm Sonnar, but this is probably because the lab printed the Variogon shot darker than the Sonnar frame, resulting in some marginal loss of detail in some highlights in the Sonnar shot.  For all practical purposes, given equivalent printing, I would think that it would not be possible to distinguish between the 300mm Carl Zeiss Jena Sonnar and the 140-280mm Schneider Variogon.

You can compare the sizes of 300mm lenses and data about them here.

150mm × 2

I also decided to compare the Arsenal 150mm Kaleinar + Arsenal 2× converter.  Even with f/2.8 set on the lens, the results are very good indeed, in terms of both contrast and sharpness in a large part of the central area of the image.  At f/11 the roof tiles near the top edge of the image are much sharper, with a small fall-off in the corners.  Definitely not up to the definition of the CZJ 300mm Sonnar, even at full aperture!, but not far behind.  This combination is definitely very useable if you don’t have the 300mm lens, or don’t want to carry the extra weight around with you on a given occasion.

Another combination is the Schneider 150mm Tele-Xenar + Schneider 2× converter.  Used on its own, at maximum aperture, this lens was much sharper than the Kaleinar, but at f/11, I could not distinguish (even with the loupe) between the Tele-Xenar and the Kaleinar shots.  So we can expect similar outstanding results when the Tele-Xenar is tested with the Schneider converter, although I did not shoot with this combination.  (My car had been parked in a no-parking zone for several hours, and the traffic wardens and local police had shown great understanding and patience when I explained that I could not possibly carry all these lenses in order to complete the tests, but I finally felt that the time had come to pack up and go home!)

To go on to the next section, a full review of the Kilfitt 300mm Pan-Tele Kilar, click here.

For the results obtained with the Kilfitt 150mm Tele-Kilar used with the Kilfitt Multi-Kilar variable converter at the 2× setting, see here.

[C302-3: Carl Zeiss Jena 300mm Sonnar at f/11  1/125 sec]
To go back to the beginning of the lens tests, click below and then choose the focal length that you want to read about.

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© TRA January 2002  Latest revision: November 2020