Explore Scientific 1.25" 68° Series Argon-Purged Waterproof Eyepiece - 20mm
Through computer-optimized design, a careful selection of optical glasses, and enhanced multi-layer deposition coatings, the Explore Scientific 68° Series eyepieces produce long eye-relief and ensure high image-correction, a flat field, and high contrast across the entire image field. An excellent choice for those who make extended visual studies of detail with subtle variations of brightness, and for those who must wear glasses while observing.
With the introduction of the 68° Series, Explore Scientific has made two important improvements in eyepiece manufacture - the first being 15 layer Enhanced Multi-layer Deposition (EMD) coatings on all glass-to-air surfaces to gain maximum contrast, and waterproofing the eyepiece with the use of Argon gas purging instead of standard Nitrogen gas. Although Nitrogen is a fine choice that will last for many years, Argon is a larger molecule that maintains its protective properties over a wider range of temperatures, and is even more resistant to diffusion thereby further extending the protective waterproof environment of the eyepiece body.
Each eyepiece is meticulously assembled into precision machined metal lens barrels that maintain the perfect alignment of the optical train for years of rugged use in the field. To keep internal reflections to a minimum, all internal surfaces of the eyepiece barrel are flat black, as well as the edges of the lenses themselves to minimize the scattering of light within the lenses themselves.
Explore Scientific's eyepieces are backed with their exclusive Explore STAR Transferrable Extended Life of the Product Warranty. Limited Warranty is one year, which converts to the Explore STAR Transferrable Extended Life of the Product Warranty when product is registered within 60 days of purchase. We think that you will find Explore Scientific eyepieces rank among the finest obtainable and represent an outstanding value.
Mar 26, 2018
ES 20mm 68 degree eyepiecePros: Cons: Comments:
This is another fine eyepiece with good color, contrast, sharpness and overall comfort in use. I like the 68 degree field of view more than wider fields. It's easier to use and better for eye placement in my experience. The materials and finish are very high quality. It is not a small eyepiece, but is manageable. All my filters thread in smoothly. The only thing I don't like is the 'safety' tapered barrel. It doesn't hang up in diagonals, but it doesn't allow some of my twist adapters to tighten very well. Over the past many decades I never had any trouble with plain, straight sided barrels. Maybe somebody will discover those again as a 'new' innovation.Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comJun 3, 2013
Seems to be goodPros:
Quality LensesCons: Comments:
I compared this one with my TMB 9mm, and this one gives wider field of view (naturally!) and slightly higher performance. The finish is good.Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comMar 22, 2013
Explore Scientific 20mm eyepiecePros:
Strong Construction,Quality LensesCons: Comments:
This eyepiece is excellent in build quality and gives excellent views on my 5" refractor. I use it with my solar wedge and for general night sky observing. It is one of the 68Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comFeb 9, 2013
20 MM 68 DEGREE EYEPIECE GREAT VALUEPros:
Ex Value Great Optics,Quality LensesCons: Comments:
USE TWO OF THESE 20 MM IN A BINOVIEWER. WORKS UNREAL!! VERY GOOD CONTRAST AND FLAT FIELD OF VIEW, SEEMS LIKE YOU ARE TRAVELING THROUGH SPACE. USE ON A FIVE INCH REFRACTOR. VERY NICE WIDE FIELD. HIGHLY RECOMMENDED!!Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.com
- Skill Level
- Time with Product
Dec 9, 2012
- User Notes:
- Review by Scanning4Comets of Canada.
20mm ES a real winner!Pros:
Strong Construction,Accurate,Compact,Easy to Use,Quality Lenses,LightweightCons:
No cons at allComments:
The 20mm Explore Scientific is a really nice eyepiece. I mainly use mine for deep sky observing, but it also served up well as a planetary eyepiece with a barlow. Highly recommended!!!Bottom Line: Would you recommend this item? Yes
This review was provided courtesy of AgenaAstro.comSort by
Apparent Field of View 68° Barrel Size 1.25" (31.7mm) Bolt Case Included Yes - Free Agena Eyepiece Container Bolt Case Size Agena 65x80mm Coatings EMD (Enhanced Multilayer Deposition) Coatings Design 6 Elements; Combination of: Dense Crown, Light Crown, Dense Flint, and Lanthanum Optical Glasses End Caps 2 Eye Relief by Design 15.3mm Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6) Focal Length 20mm Lens Elements 6 Lens Groups 4 Parfocal Yes Rubber Eye Guard Rubber Folding Type Blackened Lens Edges Yes Additional Information Body: Anodized Black Aluminum; Laser-Etched Description and Serial Number; Rubber Grip: Internally O-Ring Sealed and Argon Purged
Barrel: Stainless-Steel, Double Taper, Accepts Standard Filters
Manufacturer Explore Scientific Eyepiece Focal Length 15.1mm - 20mm Eyepiece Field of View 61 - 70 degrees Eyepiece Series Explore Scientific 68° Barrel Type Tapered barrel Eyepiece Weight 8.70oz (246.64g)