It's also an f/2.8 and FX. A same size Z DX 28/2.0 or 1.8 with metal in the build would appeal to me. This lens is clearly intended to be "relatively" inexpensive.
Dave
Not a lot has been said about the new 28mm lens yet. I agree it would have been nicer if it were faster than f/2.8. Even f/2.5 would be nice, making it a useful half stop faster than zooms covering the same focal length. I think f/1.8 or f/2 in the same size would compromise the optical design too much, or would have to be a DX lens. To maintain the same optical standards of the other FX 1.8 primes, it would need to be at least as big as the Z 35/1.8.
The outer appearance is obviously designed to mirror the older AI and AIS lenses. The lower part is styled like the old aperture rings but it appears to be a fixed part of the barrel. It's disappointing that it does not have a real aperture (or control) ring. In this respect I prefer the design of Fuji and Sony lenses with their dedicated aperture rings. I guess this section provides a useful surface for gripping the lens when attaching or removing from the camera, but the lens also has a chrome grab-ring similar to AI lenses. So much of the styling of this lens is for show rather than functional. I guess the "focus ring" can be configured to control the aperture or exposure compensation like the f/1.8 primes. Maybe this is useful a useful feature but it seems odd to control these functions using a focus ring
It even keeps the same 52mm filter size as AI lenses. I think it is a shame the new Z 50mm micro, 24-50 and 16-50 don't share the same filter size, it would be nice to see some standardization in Z lenses.
The optical design is interesting, with a small front element and progressively larger lenses towards the rear, including two aspherical elements. It focuses to 0.19m, a shade less than the AIS 28/2.8. The maximum reproduction ratio is only 1:5, compared to 1:3.9 for the AIS lens, probably due to focal length shortening at close range.
The MTF is very high within the DX image circle. Performance towards the FX corners drops off but is still relatively good: