TeleVue Nagler Zoom Eyepieces
The TeleVue Nagler Zoom eyepieces are available in two options - a 2mm-4mm Zoom and a 3mm-6mm Zoom. Both are 1.25 Inch format. Both eyepieces features five elements in three groups and both have an apparent field of view of 50 degrees. Each has an eye relief of 10mm and both weight about 5.5 oz.
The Nagler Zoom telescope eyepieces are best used as planetary eyepieces in shorter focal length refractor style telescopes. Most Schmidt-Cassegrain telescopse will not pair well with the Nagler Zoom eyepieces because of their long focal lengths. For example, a 12" SCT with a 3000mm focal length (f/10 focal ratio) would have 500x to 1000x magnification in the 3mm-6mm option. This is simply far too much magnification for any practical use in the majority of sky conditions. Even in the most perfect of steady sky nights, 500x magnification is just simply to much, and 1000x would never be useful.
The Nagler Zoom eyepieces are best used in shorter focal length telescopes. For example in a relatively standard 80mm aperture, 480mm f/6 refractor telescope, the 3mm-6mm Zoom would output 80x to 160x and would be a fantastic choice for lunar and planetary observations.
It isn't every night that atmospheric conditions will allow high-power viewing, but anyone can tell you that when those perfect evenings happen, being able to get ultra-close is breathtaking. To study Saturn's ring structure up close or get every last detail of on the surface of Jupiter may only happen a handfull of evenings a year. For tweaking out the last bit of power that the atmosphere will permit, the TeleVue Nagler Zoom eyepieces are the best tools you can have.
Award Winning Eyepieces
The TeleVue Nagler Zoom 2mm-4mm was awarded Sky & Telescope Hot Product of 2004 and the Nagler Zoom 3mm-6mm was awarded the same award in 2001.
Parfocal at all focal lengths
A great feature of the Nagler Zoom eyepieces is they are parfocal at each focal length. When changing from 3mm to 6mm the focas remains the same. Many other zoom eyepieces require changes in focus where the TeleVue Nager Zoom does not. (minor tweaking may be necessary)
