Nagler 17mm T4 vs Nagler 16mm T2
I have both and have compared them in a couple of different scopes.
The 17mm Nagler is my favorite of the new type 4's, and has better contrast and
slightly better edge sharpness than the 16mm. The 17mm also has more eye
relief, though almost to much if you don't wear glasses. Also the 17mm has a
slight bit of the dreaded "kidney bean" effect if you get your eye to close to
the eye lens.
The 16mm offeres a bit more of that spacewalk feel, no kidney bean effect, and
can be used in both 1-1/4" and 2" focusers.
The 17 can only be used in a 2".
I think that the 16mm may be a tad sharper on axis, but gives away some edge
sharpness to the 17mm. It is obvious the 17mm has the better coatings when
comparing the two.
The 17mm is big and heavy compared to the 16mm. The 16 to me gives more of that
spacewalk feel, but it's really a close call.
If you wear glasses, the 17mm is really the best choice. If you don't, it's a
>Has anyone in the group done a careful comparison of these two eyepieces? I
wonder how they compare for edge sharpness and that "spacewalk" effect.>