I finally got around to trimming a focusing adapter for the Oude Delft Rayxar 50mm f/0.75 lens, to allow it to be used for infinity. The problem with this lens is of course the extremely short back focus, around 0.8 (!) mm, which means that during experiments, the likelihood of scratching the sensor is
very high. In fact, it is near unavoidable.
In the previous attempt, I damaged the shutter cover curtains on my Z9. This won't prevent the camera from being used, as the curtains only functions as a dust shield in front of the sensor (there is no mechanical shutter at all). However, seeing how easily one can unintentionally scratch the sensor surface led me away from using the Z9 for more experiments of this kind. The tiny Z30 is rather inexpensive, provides a lot of pixels to allow full use of the 50mm "X-ray" optics, and happily accepts my Rodenstock TV-Heligon 50mm f/0.75 even for infinity (ab)use; however the internal opening is insufficiently wide for the rear portion of the Rayxar even when the metal shroud around the rear optical block is removed. Besides, the lack of a viewfinder hampers the field use and critical focusing unless the camera is tripod mounted. Which means I should be better off with a finder-equipped body like Zf, Z6, or Z7. Due to the finder overhang, adapting these monster lenses for Zf although possible is not straight forward, so I decided to experiment with a spare Z6 floating around, and aim for final use on a spare Z7.
My experiments are not completed, but I found it necessary to add internal shims to my bespoke mount to ensure the rear part of the Rayxar did not come into contact with the sensor surface. One can readily imagine why this measure was required
.
Anyhow, I have now verified the Rayxar 50/0.75 indeed can focus to infinity on the chosen Z Nikons, and due to the shims the scratching danger is mitigated (to some extent).
A proof of concept is shown below, by Z6. Focus here is set to around 100m, to allow the buildings to reside inside a zone of passable sharpness. I had initially focused on the hilltop in the background, but then the frames mostly contained subjects badly out of focus. Thus deemed a little closer would be better. About 20 frames stitched in PTGui. I did these captures with a hand-held camera and didn't fine-tune the stitching, thus there might be the odd mismatch in the final image. However nothing major, presumably.
