Hello Rob
Thank you for this. It is this sort of factual information and the results of tests that I need. Perhaps I should have obtained this before buying the lens!!
As so-called “6x6 format” is not a 6cm × 6cm square, I hope that I may be able to get away with it – always assuming I can get the lens far enough back into the camera to obtain infinity focus!
Hasselblad specified the intended usable dimensions of the film image in “6x6 format” at 54mm × 54mm – even though the image recorded on the film is slightly bigger than this, generally 56mm × 56mm and sometimes a little larger, depending on the camera manufacturer and model.
For a square 54mm × 54mm, the diagonal is a little under 76.4mm, so it might be worth trying – if, as I say, making a suitable mount is possible.
If I am prepared to crop a little off two opposite sides, to create a rectangular image, I might be there. For instance, with a usable area of 54mm × 50mm, the diagonal is fractionally under 73.6mm. Considering the usable area to be 54mm × 48mm, the diagonal is 72.25mm, and for 54mm × 45mm, the diagonal is just under 70.3mm.
I could thus use a Pentacon Six camera to create images in either portrait or landscape orientation – and without needing to turn the camera through 90°.
The manufacturers of shift lenses often specify the limits to shifts, in order to obtain images with acceptable quality into the corners, and some shift lenses for “6x6” cameras specify that beyond a certain amount of shift, 10mm, for instance, a reduced area of the image (for instance, 6 × 45) should be used. See for instance here:
Wiese Fototechnik shift & shift/tilt lenses
On the basis of these calculations, I am prepared to explore the possibilities further.
I will report back here, but given the current situation, several weeks may need to pass before I can take the next step!
Thank you again for your help!
Trevor