Explore Scientific N2 20mm 68° 1.25″ eyepiece
Looking for an eyepiece that gives you a truly immersive view of the night sky and still performs well in demanding conditions? The Explore Scientific 68° series eyepiece with a 20mm focal length is exactly what you need. It combines a 68° apparent field of view, premium optical design and a robust waterproof body filled with inert gas - all in a compact 1.25″ barrel format.
Optical design
This eyepiece is built as an SWA (Super Wide Angle) design with 6 lenses in 4 groups. This configuration delivers excellent image sharpness not only at the center but also at the edges of the field. That is especially important when using the eyepiece with fast telescopes (low f/ ratio), where cheaper eyepiece designs suffer from coma and astigmatism toward the edges.
The patented EMD multi-layer coatings, combined with blackened lens edges, effectively suppress unwanted reflections and ghost images. The result is a sharp, accurate and high-contrast image from the center all the way to the edge of the 68° field - exactly what a quality astronomy eyepiece should deliver.
Waterproof and nitrogen-purged body
The hermetically sealed, nitrogen-purged construction protects the eyepiece against moisture, dust and fungus on internal optical surfaces. Internal condensation is virtually eliminated - even during the significant temperature changes that are completely normal during nighttime astronomy sessions. This design also makes maintenance easier: the external surfaces can be cleaned with standard cleaning products without any risk of liquid getting inside.
Comfort and usability
The eyepiece comes with fold-down rubber eyecups that you can adjust depending on whether you observe with or without eyeglasses. The 15mm eye relief is comfortable and allows relaxed viewing even for eyeglass wearers. Other practical features include:
- Metal stainless steel barrel with a standard 1.25″ filter thread - compatible with any standard astronomy filter
- Conical locking groove that prevents the eyepiece from accidentally slipping out of the focuser
- Fold-down rubber eyecup for flexible positioning of your eye
Parfocal compatibility within the 68° series
The entire Explore Scientific 68° series is parfocal - meaning that when you switch between eyepieces of the same series, you do not need to refocus. This is extremely convenient during visual observation or when comparing objects at different magnifications.
Why choose Explore Scientific
Explore Scientific is a brand with a long tradition in premium astronomy optics. Their 68° series eyepieces are popular among visual observers and experienced amateur astronomers because they offer serious optical performance at a comparatively accessible price. Waterproof nitrogen-purged construction, patented EMD coatings and parfocal series compatibility are features that are not always standard in competing products within the same price range.
Whether you observe from a balcony, a field or a mountain observatory, the Explore Scientific 68° series is a very solid and reliable choice for years of use.
Technical specifications
| Parameter |
Value |
| Series |
Explore Scientific 68° |
| Focal length |
20mm |
| Apparent field of view |
68° |
| Barrel diameter |
1.25″ |
| Optical design |
SWA - 6 lenses in 4 groups |
| Coatings |
Patented EMD multi-layer coatings, blackened lens edges |
| Eye relief |
15mm |
| Eyecup |
Fold-down rubber |
| Barrel material |
Stainless steel |
| Filter thread |
Standard 1.25″ |
| Waterproof |
Yes |
| Gas filling |
Inert gas (nitrogen) |
| Parfocal |
Yes - within the 68° series |
