Yes, I am a notorious pixel-peeper, especially with shots from various telephoto lenses. If a lens renders a relatively crisp image at 200% (~113 ppi) on my screen, I’m usually satisfied with it.
With past copies of the Nikon 300mm PF paired with the TC-14E III, I’ve had no problem with that criterion whenever the camera body managed to focus the lens correctly. But now that I’m shooting my most recent copy on Z7 and Z50, both of which have superbly accurate autofocus, it seems that either lens or teleconverter is the weak link.
Over the course of several outings I’ve shot both the 90-280mm SL and the 300mm PF/1.4X at known targets. With enough samples now to offset any differences in weather, heat shimmer, etc., a detailed comparison has revealed what I’ve long suspected: the 90-280mm captures very nearly the same amount of discernible detail as the 420mm F-mount combo!
No, not exactly the same, and not on every target. But aiming at text on distant signboards or placards, I can read as much from the SL lens’s shots as I can from the Nikon’s about 80% of the time. And the sense I get is that the limiting factor with the 90-280mm SL lens is the camera’s sensor.
Bad Nikon sample? Or is it that the 90-280mm is just so good that it has now spoiled my impression of a heretofore respected lens? Dunno, but I do know which one I’ll have with me 90% of the time I head out the door…