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Tele Vue 1.25" Nagler Planetary Zoom Eyepiece 2-4mm

5.0 (1 Reviews) Read Reviews Write Review
Brand TeleVue
Part Number ENZ-0204
Availability available

Product Info

Manufacturer Description

The 2-4mm Nagler Zoom is recommended for fast, high performance scopes of 800mm focal length or shorter, such as the Tele Vue-60. It has click-stops every half-mm.

Concept / Background: I did not set out to design a zoom eyepiece, per se. David and I were discussing characteristics we'd like in a superior "planetary" eyepiece, and the zoom feature answered one of the major goals; how to obtain the highest possible useful magnification on a given night considering the ever-changing atmosphere. There were other aspects of equal importance and only the combination of all would satisfy our ethos in creating a "planetary" eyepiece: full field sharpness for any speed telescope, high contrast and transmission for natural color rendition, low scatter, and comfortable eye-relief. Being a zoom, we also concerned ourselves with making sure it was parfocal through the zoom range as well maintaining a constant apparent field of view. The one aspect we were not too concerned with was giving the eyepiece a wide AFOV.

Limiting the AFOV to 50° and the eye-relief to 10mm, we were able to create a compact physical design employing only five elements to reach the optical goals. Like other "Naglers," it utilized a negative lens group ahead of the focal plane. This permitted relatively long eye-relief for very short focal lengths. By independently moving the upper and lower lens groups, we achieved constant focus (parfocality), constant apparent field of view, and essentially constant eye-relief. Just by rotating the upper barrel, you can zoom through the power range. Click stops offer known power points for reference without needing to look at the barrel and instantaneously choose the optimum magnification for the given observing conditions.

I was sufficiently confident in the design and purposely decided to attach my name to the zoom, despite the common association between "Nagler" and 82° AFOV. I felt it was more important to stake our reputation on overcoming the "degrading zoom reputation" than maintaining the 82° assumption for "Nagler" designs.— Al Nagler


5.0 (Based on 1 Reviews) 100% of reviewers recommended this product.
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      User Notes:
      Review by haker of Sugar Grove, NC.
      May 31, 2015

      5.0 Great for planets at high magnification


      Easy to Use,Quality Lenses



      I have a complete set of orthos down to 4mm for viewing planets. Below that I was forced to barlow which is inconvenient when you need to start at high magnification and then back off as necessary. This quality eyepiece allows starting at high magnification at the 2mm setting (750x for me) and backing off to 4mm (375x for me) in half mm increments without swapping parts. Worth every penny.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Apparent Field of View 50°
      Barrel Size 1.25" (31.7mm)
      Bolt Case Included Discontinued Item
      Bolt Case Size Agena 42x60mm
      Coatings Fully Multi-Coated
      Design Nagler
      Max Width 1.7" (43.2mm)
      Eye Relief by Design 10mm
      Field Stop Diameter 1.7mm - 3.3mm
      Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6)
      Focal Length 2mm
      Lens Elements 5
      Lens Groups 3
      Parfocal Yes
      Rubber Eye Guard Yes
      Blackened Lens Edges Yes
      Manufacturer TeleVue
      Eyepiece Focal Length Variable Range
      Eyepiece Field of View 51 - 60 degrees
      Eyepiece Series Tele Vue Nagler
      Barrel Type With safety undercut
      Eyepiece Weight 5.70oz (161.59g)