I finally had a short opportunity with some blue skies to do some quick test shots today, the lens certainly deliver adequate sharpness corner to corner no issues at all, here shot at f/11 with some shift, a typical architecture setting, no tilt as this was handheld, I just wanted to see how well the 19mm holds up on the D810.
_EGL9159 by
Erik Gunst Lund, on Flickr
Fore and background are rendered nicely and camera/lens handles the trees/branches and the light post very well against the very bright sky, tiny amount of CA is handled nicely by ACR
Much more shooting is required to see how aperture setting change the sharpness for this combination - Here the detail holds up well for my purposes at f/11!
So far very happy also with the build quality of the 19mm
I think a dedicated lens collar could be so nice for tripod work. Tempting to do stitch-shifting with this lens!
There is a nice cylindrical bit where the name plate is located, could clam onto that - It seems the shift control is unaffected even with the extra weight of the big battery grip on the D810, holding onto the lens and turning the shifting up or down.
Tilt is then fixed at a constant angle, if needed, but that should work for stitching,,,