Roy P writes:
It looks like the Nikon 28mm f/1.4 isn’t quite in the same league as the Nikon 105mm f/1.4. Am I right?
Looks like the Fujifilm medium format isn’t quite ready for prime time.
DIGLLOYD: it is far more difficult to achieve performance across the field in a 28mm f/1.4 than with a 105mm f/1.4, and Nikon has chosen to keep the lens size small and price moderate, if about $2k can be considered moderate! The relatively small lens size makes it even more of a challenge. In the central 1/2 of the frame, the Nikon 28/1.4 is outstanding even wide open. Outside that area it needs stopping down. It has beautiful rendering and I like the lens, but it is not an Otus across the imaging field.
It is far more difficult to keep performance high at 28mm than with a 105mm. As the Otus 28 demonstrates: the Otus 28/1.4 has significantly less good MTF wide open than the Otus 55/1.4 MTF or Otus 85/1.4 MTF . Those are not just graphs and numbers, but visible in their effects in real images. The lower MTF at f/1.4 at 28mm is not a coincidence—in a 28/1.4, correcting aberrations is like herding cats. So it's apples and oranges to compare 28mm and 105mm performance—the expectations must be in line with reality.
In reference to Fujifilm medium format , Roy is referring to the focus instability I have observed with every Fujifilm GF lens (such as the Yellow Bike glitch), except perhaps the GF 23mm f/4 , but a 23mm f/4 hides such behaviors better. I have little doubt that it too will misbehave since I deem it a Fujifilm GFX electronic brain-fart bug which I first observed with Fujifilm X five years or so ago—a genetic defect. The GFX sensor is fantastic, so this behavior is terribly disappointing, but it won’t bother or even be noticed by many people since they’ll shoot one frame at f/8 or f/11 or whatever and be oblivious to small errors.