Tested on Canon EOS R 30M sensor. Leica R and Contax lenses are adapted to Canon RF mount via Novoflex adapter.
Sony FE lens is tested with A7R V with image resampled to Canon EOS R @ 30M resolution.
The test is performed in a dark room with a single Rotolight Neo light mounted on the camera hotshoe. The Rotolight is set to 5600K color temperature @ 70% light output. The distance between the camera and the test target is about 1.5m. The camera is set to all manual mode and exposure is measured via Gossen Luna Pro F.
Images are imported into Adobe Lightroom, lens profile and compensation are turned off and all images are set to white balance 5600K with 0 tint. Images are then exported at the original resolution (except Sony which is reduced to the exact resolution as Canon EOS R).
I don't own any Nikon lenses anymore and cannot provide any samples. The center of the frame is enlarged to 200% and captured for comparison.
Anyone interested in the original full-resolution file, please feel free to download it from here. You can also click on the lens model to download the image for the specific lens.
For whatever it is worth, judge for yourself...
