Weirdness. EPhotozine reviews already often show a bit odd MTF results, but this is just weird.
This lens tested in EF mount on 5DS R:
https://www.ephotozine.com/article/samya...view-31895
https://www.magezinepublishing.com/equip...222492.jpg
This is sort of as expected: Due to high res. sensor is f5.6 already affected by diffraction limiting. Stopping down from f2.8 to f4 increases sharpness.
Now the weirdness. The same lens with Nikon F-mount tested in D850:
https://www.ephotozine.com/article/samya...erformance
https://www.magezinepublishing.com/equip...509381.jpg
Similar resolution sensor... Similar peak resolution, but at f8 instead of at f4, even though f8 should be affected by diffraction softening already. Something is off with these "measurements".
This lens tested in EF mount on 5DS R:
https://www.ephotozine.com/article/samya...view-31895
https://www.magezinepublishing.com/equip...222492.jpg
This is sort of as expected: Due to high res. sensor is f5.6 already affected by diffraction limiting. Stopping down from f2.8 to f4 increases sharpness.
Now the weirdness. The same lens with Nikon F-mount tested in D850:
https://www.ephotozine.com/article/samya...erformance
https://www.magezinepublishing.com/equip...509381.jpg
Similar resolution sensor... Similar peak resolution, but at f8 instead of at f4, even though f8 should be affected by diffraction softening already. Something is off with these "measurements".