The external optical surfaces of the eyepiece are treated with permanent “LotuTec" coatings. These special hydrophobic (water-repelling) coatings are so smooth, even at the molecular level, that water can find virtually no grip on the optical surfaces. This causes the condensation from rain, fog, snow, or your own breath to form in much smaller droplets than on standard optical coatings. Smaller droplets scatter less light, resulting in higher light transmission and a clearer image. Oil, dirt, and grease are similarly repelled, making for simplified, streak-free cleaning.

The eyepiece has a pull-up rubber-rimmed eyecup, so you won’t have to worry about a rolldown eyecup deteriorating with age as you do with other eyepieces. A slight twist of the eyecup locks it in place when it is fully extended. It comes with a Cordura-type zippered carrying case with a convenient belt loop for no-hands carrying. There are dust covers for both ends of the eyepiece.

The eyepiece is marked with magnification points for both 65mm and 85mm Zeiss scopes, so there’s never any guesswork about what the magnification might be. However, as with any zoom eyepiece, the precise focal length or magnification of this Zeiss zoom at any given point in time is not all that important. The experienced observer invariably adjusts the zoom magnification to match the seeing conditions, distance from the subject, and subject size as he looks through the eyepiece. This is preferable to first setting the zoom to an arbitrary focal length value according to the scale on the side of the eyepiece and using it at that power no matter what the seeing conditions.

For use with 65mm Zeiss Victory Diascope spotting scopes . . .
The zoom at 15x has a very wide 168' field at 1000 yards and 15mm eye relief.
At 23x it has a 120' field at 1000 yards and 10mm eye relief.
At 30x it has a 102' field at 1000 yards and 11mm eye relief.
At 45x it has a 78' field at 1000 yards and 12mm eye relief.

For use with 85mm Zeiss Diascope spotting scopes . . .
The zoom at 20x has a good 129' field at 1000 yards and 15mm eye relief.
At 30x it has a 93' field at 1000 yards and 10mm eye relief.
At 40x it has a 75’ field at 1000 yards and 11mm eye relief.
At 60x it has a 60' field at 1000 yards and 12mm eye relief.

The flexibility of a zoom eyepiece to instantly match the magnification to changing lighting or seeing conditions is one of the zoom eyepiece’s chief advantages. Match that flexibility to Zeiss-grade optics and you have an exceptional optical tool for any nature lover.