Hi everyone,
I recently acquired a Cambo Actus G and some Mamiya RZ67 lenses. On the back I use a Nikon Z7 or Panasonic S1R. I have been getting fantastic results with that setup. Sharp across the frame and right into the fully shifted edges albeit with (expected) strong vignetting in the extreme corners at 15mm of rise.
Newly arrived from eBay is a "Mint" used Rodenstock 55mm APO Sironar Digital (Copal 0) and the corresponding lens plate from Cambo. I started testing it this morning on the Actus, with both the Z7 and S1R. I tested at f8, f11, f16 and f22. I tested it on my back fence 3 metres away and on another subject (a line of houses and trees) 150 metres away.
When focused in the centre of the frame, the centre is sharpish but the edges are very soft. Not mush perhaps, but pretty close. This was the case for both near and far subjects, with both cameras and at all apertures, although f22 was slightly better but otherwise to be avoided due to dulling from diffraction. I was surprised and disappointed.
When shifted, the edges are even worse. The focus peaking 'shimmer' clearly shows a circular zone of high contrast/sharpness that widens and narrows somewhat with focus and aperture changes. To me this suggests field curvature, although Rodenstock state that for the APO Sironar Digital lenses "special attention was given to the correction of the curvature of field."
However there are no circumstances in which I can achieve satisfactory focus in the outer third of the frame. This is my first Rodenstock lens.
Electronic shutter, 2 second timer, RRS tripod, zoomed live view focus, with peaking.
Is there something obvious (to you) that I am missing here? Perhaps I have an issue with the lens itself? Perhaps the way I have attached it to the lens plate with the retaining ring is incorrect, but I don't think so. Any advice would be gratefully received.
Thanks in advance,
Steve.
100% crops below, shot at the local park this morning.
First, the full scene.
Centre
Left
Right
I recently acquired a Cambo Actus G and some Mamiya RZ67 lenses. On the back I use a Nikon Z7 or Panasonic S1R. I have been getting fantastic results with that setup. Sharp across the frame and right into the fully shifted edges albeit with (expected) strong vignetting in the extreme corners at 15mm of rise.
Newly arrived from eBay is a "Mint" used Rodenstock 55mm APO Sironar Digital (Copal 0) and the corresponding lens plate from Cambo. I started testing it this morning on the Actus, with both the Z7 and S1R. I tested at f8, f11, f16 and f22. I tested it on my back fence 3 metres away and on another subject (a line of houses and trees) 150 metres away.
When focused in the centre of the frame, the centre is sharpish but the edges are very soft. Not mush perhaps, but pretty close. This was the case for both near and far subjects, with both cameras and at all apertures, although f22 was slightly better but otherwise to be avoided due to dulling from diffraction. I was surprised and disappointed.
When shifted, the edges are even worse. The focus peaking 'shimmer' clearly shows a circular zone of high contrast/sharpness that widens and narrows somewhat with focus and aperture changes. To me this suggests field curvature, although Rodenstock state that for the APO Sironar Digital lenses "special attention was given to the correction of the curvature of field."
However there are no circumstances in which I can achieve satisfactory focus in the outer third of the frame. This is my first Rodenstock lens.
Electronic shutter, 2 second timer, RRS tripod, zoomed live view focus, with peaking.
Is there something obvious (to you) that I am missing here? Perhaps I have an issue with the lens itself? Perhaps the way I have attached it to the lens plate with the retaining ring is incorrect, but I don't think so. Any advice would be gratefully received.
Thanks in advance,
Steve.
100% crops below, shot at the local park this morning.
First, the full scene.
Centre
Left
Right
! Images seem to be nice and crisp now. Hope you resolve you issue!
