Our test scene, at f/2.8 the f/2 AI was about .2 brighter.
I find the 28mm f2 slightly better in the center.
While in the corners the 28mm f/2.8 AIS is far superior.
At f/4 the color and exposure on the Nikon lenses is identical, truly
impressive. The Sony Zeiss is darker at f4.
At f/4 the 28mm f/2.8 AIS seems to have just a touch more contrast and
less fine detail. Nothing that will be noticed in real world use.
The exposure for the Sony Zeiss zoom was pulled up + .35 to match the
Nikkors. Just a touch more fine detail, perhaps that famous Zeiss
The 28mm f/2.8 AIS is still ahead in the corners.
Now the Sony Zeiss zoom does things differently. While the extreme
corner has more detail than either of the Nikkors, the loss of detail
happens gradually and extends further into the frame. It also cheats
auto corrects the chromatic aberration.
Nothing has changed in the overall shot so I'm skipping it. The Sony
zoom still needs +.30 exposure to match the Nikkors at f5.6, which are
hard to tell apart.
Slight color difference and maybe a touch more detail with the Sony
Both Nikkors improve at 5.6 in the corners but the 2.8 AIS says ahead.
Oddly enough the Sony Zeiss 24-70mm f/4 FE doesn't really improve by
stopping down. Except in the last 300 pixels of a 24mp image both
Nikkors best it.
At f/8 the Sony Zeiss zoom needs +.25 exposure to match the Nikkors and
diffraction starts to affect them all.
The Nikkor story continues, both improve a little but the very extreme
corner isn't quite there. They both got some help from the automatic
chromatic aberration fix in photoshop.
The Sony Zeiss, well it's a confusing lens.
The Sony Zeiss zoom at f/4 and f/8. Is it me or does the extreme corner
get better while the railing is worse, perhaps because the vignetting
helps it have contrast at f/4?
Diffraction takes a toll at f/11 and they all look the same in the
center. The Nikkors finally reach the very far corner.
As for the Zeiss it's rather embaressing.
On to more in part two