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

The teleconverters

There are at least three 2× teleconverters in the Pentacon Six mount:

Other 2×  converters

There are some other teleconverters with the Pentacon Six mount, but these appear to be variants of the top two converters listed above.

For this website I have compared the three 2× teleconverters with each other and with the Vivitar 2× teleconverter manufactured in the Hasselblad mount.  The 2× Kiev converter is much sharper than the Panagor. The Schneider 2× converter is better still, on a par with the Vivitar 2× converter in Hasselblad mount, or perhaps even better than it.

[C372-26A: three 2× converters with Pentacon Six / Exakta 66 / Kiev 60 mount, plus a Vivitar for the Hasselblad 500C
Front right is the Arsenal 1.4× converter]

The Vivitar 2× converter for the Hasselblad stands out immediately as being much bigger and heavier than the other converters.

Report on the Hartblei 2× converter

You can see a report on the Hartblei 2× converter here.

Incompatibility limitations with the Joseph Schneider 2× converter

It is the shape of the Schneider 2× converter that is most different from all other converters with the Pentacon Six mount. As with the Carl Zeiss Oberkochen 2× converter for the Hasselblad, the front element of the Schneider converter is mounted at the end of a narrow tube a long way forward of the front mount of the converter. This means that it protrudes into the back of the lenses with which it is used, resulting in some compatibility problems. Although the Exakta 66 manual says that the 2× converter can be used with the 80mm lens, this is not the case (I am sure that the manual was written before the converter was manufactured). As later Exakta 66 literature states, the Schneider 2× converter can be used with (Schneider) lenses from 150mm on up. It can be used with very few Carl Zeiss Jena or Arsenal lenses, as they mostly have a rear element that is right at the back of the lens – although it works well with the Pentacon 500mm lens – see the section on 1000mm.

[C308-17: Close-up of the rear of the Carl Zeiss Jena 300mm f/4 Sonnar lens.
The rearmost element of this lens is only just below the mount, and the Joseph Schneider 2× converter cannot therefore be mounted on this lens.
The fork-shaped connector at 11 o’clock in this view engages with a pin in the Pentacon 35mm adapter,
transmitting the aperture selected on the lens via the EDC contacts on the adapter to the metering circuits in Praktica LLC, PLC and VLC cameras.]

Close focus and converters

Converters do not reduce the minimum focussing distance of a lens, but they don’t increase it either!  The result is that with a 2× converter, you get the same image as if you had been able to get twice as close!  For example:

* I am indebted to Bob for improving on my wording here.  He points out that "The closest focus to the end of the lens (the working distance) is unaffected by a converter."  However, he goes on to say, "The 'minimum focusing distance' is measured from the image plane (film or sensor) to the subject.  This dimension actually increases by the physical length of the converter .... the subject to lens distance remaining the same and hence the camera has 'backed-up' to allow the converter to be slotted in to the setup.  In most normal applications the increase (75-100mm) is irrelevant, but it can end up being a significant percentage of the dimension when macro photography is being pursued."
Thank you, Bob, for helping me to get that clear!

So sometimes using a converter (possibly in combination with an extension tube) enables you to photograph a much smaller area.  You can see an example of such use of the 2× converter here (scroll down to the bottom).

Alternatively, if you are happy with the coverage with the standard lens, using the converter with it enables you to increase your distance from the object, thus reducing the risk of casting a shadow on what you are photographing, or of startling it, in the case of wildlife, insects or children!

Other converters

Occasionally, other teleconverters are seen.  I report on one of these on a separate page, here.

The 1.4× converter

Arsenal also manufactures a 1.4× teleconverter which has the advantage of only reducing the amount of light reaching the film by the equivalent of one stop, while 2× converters reduce the amount of light by two stops.  (This is not a fault, but a consequence of the way light rays behave when magnified.)

A front-of-lens converter

For a report of a converter that is placed in front of the lens, see here.

If you just want to see results obtained with the 2× converters, see parts of each of the following sections:

160mm   240-300mm   500-560mm     600mm 1000mm     1000-1200mm   2000mm

If you prefer to work through the whole lens test without missing anything out, click below to go on to the next section.  You will also see the results obtained with the 2× converters at the appropriate points.

If you are following the results of the lens tests, the next section is here.

If you are working through the lens data section, the next section (other converters in the Pentacon Six mount) is here.

To go back to the section on adapters, click here.

To see in detail how the Schneider teleconverter transmits the aperture information to the Exakta 66 TTL meter, click here.

To go back to the beginning of the lens tests, click below and then choose the focal length that you want to read about.
Back to beginning of lens tests


© TRA January 2002, Latest revision: August 2016