Zeiss Distagon T* 28mm f/2.0 ZF
f/2.8 Center 80% of frame is very sharp.
Slight peripheral softness.
f/4.0 as sharp as any Nikkor can get.
f/8.0 sets the perfect golden standard.
Nikkor 45mm f/2.8 P
f/2.8
60% of the center frame is already rendered quite sharply.
However the extreme left and right frame is soft.
Peripheral softness is visible.
f/4
Strangely the four corners are distinctively soft.
Whereas the center of the frame is very sharp.
Acceptable portraits at f/4.0, maybe.
Must position subject in center of the frame.
f/8.0
This lens is almost totally primed.
The entire frame is extremely sharp.
Large improvement on the peripheral sharpness over f/2.8.
Good enough for landscape photography.
Near Zeiss performance.