Given the extreme difficulty in finding a 40mm lens in the Pentacon Six mount, is it possible to adapt the Norita lens and use it on the Pentacon Six? The simple answer is, unfortunately, no! There are two reasons: the Norita lens register distance (the distance from the back of the lens mount to the film) is smaller than the Pentacon Six register distance (which is 74.1 mm) the rear of the Norita lens mount has a wider diameter than the rear of the Pentacon Six lens mount. This means that it is impossible to find any way of squeezing or adapting a Norita lens to fit the throat of a Pentacon Six, and if by removing the rear of the lens you could fit it, you wouldn’t be able to achieve infinity focus with the Norita lens, as it would be too far from the Pentacon Six film plane. A consideration of these two problems leads to the following two conclusions: as the register distance of Pentacon Six mount lenses is greater than that of Norita lenses, perhaps there might be space behind it to fit an adapter between a Pentacon Six lens and a Norita body as the rear diameter of Pentacon Six lenses is smaller than the throat of the Norita, perhaps there is further space here for some sort of adapter. The answer is: yes, this is possible – but the space is so small that making such an adapter is extremely difficult (therefore, costly), and the consumer demand is so small (or non-existent?) that no such adapter has ever entered serial production (as far as I am aware!!  – I would be delighted to be proved wrong!). However, such an adapter has been produced.  I have been told that only three units were made, and one of them can be seen in the photograph of the Norita outfit here (although it was not a Norita item!).  It is at the front of the outfit just right of centre. There are two problems in producing the adapter, and only one of them has been overcome. The Norita system has a breech-lock ring on the lens that engages with lugs on the camera body. The Pentacon Six system has a breech-lock ring on the camera body that engages with lugs on the lens. So the adapter has to have two breech-lock rings, one for the Norita body and the other for the Pentacon Six lens.  It is very difficult to build both rings within the tiny amount of space available – but it has been done! The other problem is that the auto-aperture pin on the Pentacon Six moves in and out, while on the Norita this pin moves sideways.  It has not been possible to find a way to transfer this action from the lens to the body.  Therefore, when Pentacon Six mount lenses are used on the Norita, the auto aperture or diaphragm function is lost: lenses operate all the time at the aperture selected, which makes focussing harder.  Exactly the same problem occurs with the (commercially-available!) adapter for using Pentacon Six lenses on Mamiya 645 cameras, for the same reason.  If someone can find a way of solving this problem, many Mamiya 645 owners with Pentacon Six lenses will be interested! Here is a picture of a Norita 66 with the Pentacon Six lens adapter attached:

[C392_24.jpg]

And here are two shots of Pentacon Six mount lenses on the Norita 66.  In both cases, I have chosen to show Schneider-Kreuznach Exakta 66 lenses.
 

The 150mm Tele-Xenar on the Norita [C392_22.jpg]     The 75-150mm Variogon Zoom lens on the Norita. [C392_17.jpg]

To return to the main Norita page, click here.

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© TRA February 2008