After reading some comments about this Japan Zoom eyepeice, I was curious how I will like it.
When it arrive, I could not beleive that it is SO small, and VERY light! Much smaller than I tought!
Here for comparation is RKE 28mm.
So far, I do some testing on daytime, while night obseration will wait a bit more becasue fog and clouds.....
First, Zooming is somewhat stiff. Mechanic and optic finish is SUPERB and precise!
Much more precise and nicer than Baader Mk III zoom which I recently sold.
I had a pair of Baader Mk IIIs, but did not like their weight, bulky design, and my face often touch eyepeice, even when it is screwed off upper part. Also, eye releaf for my taste, is somewhat less than I prefeer. I lke here click stop system, where I know exactly what focal lenght I have. With Nikon, you never know what FL you use.
Optically, Baader is excellent, with sharp, with not precisely circular field stop.
There is some ring on fire on Baader on edges, but MUCH less, almost none on Nikon.
What I like on Baader is that it provide more neutral toned image than Leica ASPH Zoom, which I also had, but did not like it yellowish tone of image, as well pronounced EOFB. Baader do not have any EOFB. On Nikon, still do not know.
Optics and mechanics finish, and precision, on Baader unit does not seems so precisely and well made like in Leica, while Nikon seems even more better!
Nikon provide neutral toned image, with not very sharp field stop on 21mm, while on 9mm is mushy. This actually does not bother me at all, while I most appreatiate contrast, sharpness and colour rendering.
To me, Nikon seems to have more chrystal view than both Baader and Leica, and sharpness and contrast are excellent.
FOV in Leica is largest, whiel on Nikon is smallest. Nikon at 21mm have approx 40 deg FOV, while on 9mm seems to have approx 55 deg FOV.