The Nagler Zoom! This 3 to 6 mm Nagler Click-Stop Zoom 1.25-Inch Eyepiece by Tele Vue is a planetary lens which zooms in parfocal with click-stops for every mm of extension.
This high-performance, high-contrast, and high power eyepiece is ready to take its place among the best planetary eyepieces available....but with a "Nagler" twist. Al has incorporated his proven "Nagler" concept into a zoom, while optimizing for the performance factors critical to planetary observers: contrast, resolution, and comfortable eye relief. The Tele Vue Nagler Zoom is tack-sharp across its constant 50 degree apparent field, and throughout its 3 to 6 mm focal length range, even in fast APO scopes. The 3 to 6 mm Nagler Zoom is parfocal throughout its zoom range, parfocal with other Televue 1.25-inch eyepieces, and has a constant 10 mm eye relief. Its weight is only 0.3 lb.
And, as seemingly unbelievable as it all sounds, the design includes just 5 elements in 3 groups. In case you're not counting, that's the same number of all-glass surfaces found in a Plossl or Ortho, plus a barlow!
Why did Televue design this eyepiece? By dialing in the best balance between magnification, exit pupil size, and atmospheric turbulence, the critical planetary observer can find the best possible image for their observing conditions. The new 3 mm to 6 mm Nagler Zoom features Click-Stops at 3, 4, 5, and 6 mm, full multi-coating, blackened lens edges, fold-down eyeguard, rubber grip-ring, safety undercut, anti-reflection threads, and filter threads. May the "degrading zoom" mythology rest in peace!
Tele Vue 3 mm to 6 mm Nagler Click-Stop Zoom 1.25-Inch Eyepiece Reviews
"There have been zoom eyepieces in the past, but none quite like the Tele Vue Nagler Zoom! Since the time of Galileo, short-focal-length (hence high-magnification) eyepieces have been notoriously difficult to look through. That has changed in recent years, especially with the introduction of Tele Vue's line of Radian eyepieces. The new Tele Vue zoom is small, lightweight, and offers the same magnifications (with click-stop settings) as four Radians while maintaining a constant focus and 50 degree apparent field. It also lets observers choose in-between focal lengths, thus giving them the ability to tune the magnification to atmospheric conditions, which is very critical for high-power viewing. Although the zoom's 10-millimeter eye relief isn't long enough for eyeglass wearers, it is enough to make this a very comfortable eyepiece to look through." -Sky & Telescope
OPT Product Number: TE-ENZ-0306
All Tele Vue products are available to ship world-wide from OPT, and effective July 1, 2008, are covered by a Five Year Worldwide Limited Product Warranty! Always be sure to save your original packaging materials should you need to return any Tele Vue product for warranty or repair.