Product Description
The latest computer design programs have been used to optimize its performance. Its seven element/four group design uses low dispersion and high refractive index lenses and full multicoatings for high contrast, high resolution, and flat field images across a very wide 82° field of view. The lens edges have been blackened to improve contrast.
The 4.7mm 82° Explore Scientific works with any telescope from a fast focal ratio reflector to a long focal length refractor or Maksutov. It's particularly good with Dobsonians and fast focal ratio refractors, providing high magnification with a very wide field of view for observing smaller globular clusters and compact nebulas.
At 14mm, the eye relief is surprisingly good for such a short focal length eyepiece, although eyeglass wearers will still see a somewhat vignetted image. This is not as much a problem as you might think, as the 82° field of view is so wide that even non-eyeglass wearers have trouble seeing the whole field at once. This is an eyepiece that shows you a "picture window view" of space for a true full-immersion observing experience. With its unconstricted view, your eye relaxes, allowing you to easily use the "averted vision" technique to study faint details across a huge field of view.
You can use the calculator in the "formula" tab above to see just how wide the field will be with your particular telescope. For example, it will give you a 0.54° field (slightly wider than the full Moon) at 152x with a 4" f/7 refractor like the Explore Scientific 102mm triplet apo refractor.
The eyepiece has a soft fold-down rubber eyecup and comes with dust covers for both ends of the eyepiece.
This individually serial numbered Explore Scientific eyepiece is backed by a limited one year warranty, which will be extended to an Explore Scientific transferable lifetime limited warranty when its warranty card is registered with Explore Scientific within 60 days of purchase. Here's a link to the full details on this unique transferable lifetime warranty.
Tech Details
Barrel Size | 1.25" |
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Eye Relief | 14mm |
Field of view | 82 |
Focal Length | 4.7mm |
Number of optical elements | 7 |
Weight | 7.5 oz. |
Warranty | 1 year, extendable to lifetime |
Reviews
I am definitely keeping both, with the 5mm Nagler seeing frequent use in the 85mm f7 grab-and-go refractor (TV-85) and the 4.7mm for max power in the 100MM f9 (Skywatcher 100ED).
Optically they are close. Explore Scientific did a great job with their line of 82 degree eyepieces, and the 4.7mm is one of the stand outs in this this line. At less than half the price of the 5mm Nagler it's hard to go wrong. (Posted on 10/15/2018)