Has some-one experience with the Nikkor 200mm F/4 Ai or Ai-S? Can it be compared to the 180mm F/2.8. Quality-size? How does it behave on the FX's?
Sharpness of the AI/AIS 200/4 is similar to the AIS 180/2.8 ED, perhaps a little less wide open. The 180 benefits from the ED element so is better corrected for CA, but is still not perfect.
Close-range performance is similar - the 200 focuses to 2m, and the 180 gets to 1.8m, both 10x focal length, and both achieving about 1:7.5 magnification. They perform well with closeup filters or on extension tubes if greater magnification is desired.
The 200 and 180 both have 9-blade apertures with straight sides, so the opening is distinctly polygonal when stopped down, not rounded - clearly shown in Frank's picture above. The AI 200/4 is worse - the aperture blades are a bit short so the tips intrude into the opening giving a saw-tooth effect at wider apertures. The AIS version has longer blades which fully overlap to avoid this problem so if bokeh is important I'd get the AIS version. Ignoring the shape of the aperture (which affects out of focus specular highlights) the general rendition of background is smooth with both the 200 and 180 - not surprising they are similar since both have similar 5/4 optical designs (the AF 180/2.8 has a different IF-ED design with 8/6 elements)
the 200 and 180 both have pull-out hoods which are reasonably deep and effective. Handling is similar too, although the 180 is a lot heavier and fatter. With simple helical focusing, focusing can be a little slow and heavy compared to modern designs, but it allows for careful and precise focusing.
Probably the main choice is whether you prefer the smaller, lighter 200/4, which takes 52mm filters like most other manual focus models, or the larger faster 180 which is better corrected for CA. There is also the Cosina-Voigtlander 180/4 APO which is probably better corrected than both, and focuses much closer, but it is out of production and rare, prices have risen steeply over the last few years.
Another option is the AIS 200/4 micro. I used this lens a lot some years ago, it performed extremely well on film (Velvia). I have not had much time to use it recently and it has a reputation for a lot of CA on digital cameras. Although I mostly used it at close range I did compare it a few times on with my non micro 200/4, on distance subjects it seemed to perform as well (tested on film), but my test was not exhaustive. Take the tripod foot off and it weighs about the same as the non-micro version although a bit longer and the focus ring is inconveniently far forward, so handling is not as good. However it handles extremely well on a tripod.
