The eyepiece shown in the first post is the 24/30x WF. It is shown on a 50ED where it functions as a 16x but with vignetting of the objective (and thus is not recommended for use as a 16x by Nikon).
I find that Nikon recommendation, well, "strange". Because there is some vignetting, sure, but it's not something you notice at first sight, and I use the 24/30 WF all the time on my ED50. I really like low magnifications in the woods. So, I I think Nikon may well have been a bit conservative there, possibly because that vignetting will show up it you use that eyepiece for digiscoping. Been there, done that.
Forgive me if I am wrong about this Hermann, but I think your description of early (less contrasty) versus later versions of the 30x WF are descriptions of the 20/30/38x WF eyepieces. I think you are describing use of those eyepieces as 30x on the 60ED.
You're right. I should have made that clearer. The differences between the 20/30/38x WF with the rubber eyecup and the version with the screw-out eyecup ist quite noticeable - but the old WF is still a very nice eyepiece.
As far as I know, there were not early and late versions of the 24/30x WF. The 24/30x WF has a very simple optical formula (few glass elements) so is quite bright and contrasty. I think it is at least partly multicoated. The optical design of the 24/30x MC is identical (only the metal housing and eyecup assembly is different), but it likely has updated multicoatings. I doubt you would find it better than the 24/30x WF.
Well, in a direct comparison I can see a difference between these eyepieces. It's smaller than the differences between the two versions of the 20/30/38x but the later version has more contrast.
The optical design of the 16/24/30x DS is unique. That eyepiece is huge (the largest of all traditional Fieldscope eyepieces). It is nice on the 82ED but is a monster on the 50ED.
I only ever use it on the ED82. Certainly not on the ED50, and also usually not on the EDIIIA.
I agree that the 25-75x is super sharp and contrasty, but I don't find it significantly better than the fixed eyepieces, even the WF series. I think some people who find it significantly better are fooled by the fact that, because of its narrow AFOV, it presents a very bright sharp contrasty view quite dramatically against a large field of black.
Well, I'm not sure about that. I wouldn't call it "significantly better" but it sure is good. What about "a bit better" optically? If it weren't for the small field of view I'd leave it on my scopes all the time.
BTW, Alexis, do you know the tiny 27/40/50? Very short eyerelief, very small eyepiece lens, AFOV of only 40 degrees. It may well be an orthoscopic eyepiece, it "feels" like one. An interesting eyepiece, and very small and light.
Hermann