The Pentacon Six System
by TRA

Is it possible to modify Pentax 6×7 lenses
so that they can be used on the Pentacon Six?


This is the opposite of the common question, “Can I use Pentacon Six lenses on a Pentax 6×7?”  You can find the answer to that question here.

My first question would be “Why would you want to?”  The most obvious answer would be “Because I already have some Pentax 6×7 lenses and I would now like to use them on a Pentacon Six.”  If that is the case, then it may be worth exploring.  But if you do not already have any Pentax 6×7 lenses, it may be worth considering the following:

  • the Pentax 67 lenses are harder to find than the Carl Zeiss and Pentacon lenses for the Pentacon Six;
  • they are much more expensive;
  • they have generally had heavy and occasionally rough use by professionals (i.e., they have serious signs of wear and occasionally superficial damage, dents, etc);
  • they are much heavier than the equivalent Zeiss and Pentacon lenses;
  • while optically excellent, they are not optically any better than the Zeiss and Pentacon lenses;
  • obtaining auto aperture operation on the Pentacon Six with Pentax 67 lenses is difficult and probably impossible in the space available;
  • the cost of the modification probably makes it not economically viable;
  • the selection of lenses available in the Pentacon Six mount is much greater than the selection in the Pentax 67 mount, so there is little need to turn to Pentax to get a lens for any particular photographic situation.
The register distance between the rear flange of the lens that mates with the front of the camera and the film plane is reported to be 84.95mm with the Pentax 6×7 or Pentax 67.  With the Pentacon Six it is 74.1mm.  So there is very nearly 11mm available for an adapter, plus that part of the adapter that goes within the throat of the Pentacon Six and that part of the adapter that holds onto the Pentax 6×7 lens. So that sounds possible, rather as making an adapter to mount Pentacon Six lenses on the Norita is possible (see here).
 
Update on adapter to enable 
Pentax 67 lenses to be used on the Pentacon Six:
infinity focus is impossible

I have just received the following e-mail from David Brown:
Hello:

I've heard from S.K. Grimes.  It turns out that there is 4.4 mm of material extending from the base of the bearing surface on the camera (probably part of the mount), and the auto aperture arm of the Pentax lens extends 8.8 mm (this moves side to side, not up and down like the Pentacon).  This is 13.2mm; the focal flange distance of the Pentax is 84.95 mm, and that of the Pentacon is 74.1 mm, for a difference of 10.85 mm.  The parts that stick out from the camera and the lens are thus larger than the difference in the focal flange distance, and infinity focus is impossible.

Adapters can be made without infinity focus.  I assume no one is interested; if so, please let me know immediately (it would cost approximately $250, before shipping).

Trust me, I'm pretty disappointed with this, so I'm sorry if I got your hopes up.  At least you know why no adapters exist.

Sincerely yours,
David Brown
_________________
If in spite of this serious limitation you are still interested in ordering one of these adapters, please e-mail me at this website and I will forward your e-mail to David

TRA
16th September 2011

 
Possible availablility of an adapter
to enable Pentax 67 lenses to be used on the Pentacon Six

I received the following e-mail yesterday:
I saw on your website, http://www.pentaconsix.com/p67lenstop6.htm, that you
mentioned if someone found a way to mount a Pentax 67 lens onto a Pentacon
6, to let you know.  I'm currently trying to get S.K. Grimes to manufacture
custom adapters.  I started shooting my Pentax 67 when the East German and
Eastern European cameras were harder to come by in the US, but the battery
life on the Pentax 67 is so atrocious I decided to switch, particularly
since the rebuilt Kievs seem to be a good bargain.  Assuming S.K. Grimes can
perform the fabrication, there has been a limited discussion of a
multi-adapter discount, so if you've run across others like me, pass this
along and perhaps they can get a deal on mounting Pentax 67 lenses onto
their Pentacon 6 mount cameras.
David Brown
_________________
If you are interested in ordering one of these adapters, please e-mail me at this website and I will forward your e-mail to David

TRA
15th July 2011

If you do make or get an adapter that enables you to use Pentax 6×7 lenses on the Pentacon Six, please do let me know!

To go back to the Frequently-asked Questions front page, click here.

To contact me, click here.

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© TRA July 2010, September 2011
Latest revision: March 2014