28mm f/2

[bobfriedman]

not bad in the IR either..

Nikon D800 RG1000,Nikkor 28mm f/2 Ai-S
1/50s f/5.6 at 28.0mm iso500

[longzoom]

I haven't owned a Nikkor 28/2 since the the early N- version I had for a while in the 1990's.
 I have had a ZF 28/2 for almost ten years across D3 and D800 cameras.
The ZF is heavier by 150g, and is a pretty good lens all around.  I wish it had a rubber focus grip like the Nikkors.
It has a pronounced curved field of focus way out at the edges of the 24x36 frame.  The focus plane is convex to the camera...the opposite of the common case with wide lenses.
The appearance of the curvature goes away by f/4 or so.
Here's a wide open shot that shows it:

    I've never ever seen so high level of field curvature, especially convex, produced by ZF 28/2. There is no sharpness in the central ring, at all. Sorry for asking, but is it everything OK with your copy? Is it possible there isn't any small drop of oil inside the optics, close to central area?  Please forgive me, I could be mistaken, but 2 of my former copies never acted  like this one! I had the same phenomenon when I converted old negatives to digital files, and film was not flat enough. So is it possible to post some images else, wide open? THX!  LZ 

[pluton]

    I've never ever seen so high level of field curvature, especially convex, produced by ZF 28/2. There is no sharpness in the central ring, at all. Sorry for asking, but is it everything OK with your copy? Is it possible there isn't any small drop of oil inside the optics, close to central area?  Please forgive me, I could be mistaken, but 2 of my former copies never acted  like this one! I had the same phenomenon when I converted old negatives to digital files, and film was not flat enough. So is it possible to post some images else, wide open? THX!  LZ

I will try to round up some good wide open sample shots later.  Maybe a different subject/thread would be appropriate?
RE- focus in the central section: focus was set by estimation and scale focusing, so the plane of focus ended up being a few inches behind the man in the chair, so there is no central subject in absolutely perfect focus. I posted the shot because that particular scene happens to demonstrate the curvature well. Overall, this copy of the ZF 28/2 behaves normally.