Explore Scientific N2 28mm 68° 2″ eyepiece
If you are looking for a reliable, optically high-quality eyepiece for wide-field views of nebulae, star clusters, and expansive regions of the Milky Way, the Explore Scientific 68° series eyepiece with a 28mm focal length is an excellent choice. It belongs to the popular N2 series, which has earned the trust of amateur astronomers and experienced observers worldwide thanks to its balanced performance-to-price ratio. The 68° apparent field of view offers a pleasant "window to the universe" feeling - large enough to be immersive, yet without significant optical compromises at the field edges.
Optical design and image quality
The eyepiece is built on a 6-element, 4-group optical design of the SWA (Super Wide Angle) type, which ensures sharp imaging across the entire field of view. All optical surfaces are equipped with fully multi-coated anti-reflection coatings, which maximize light transmission and suppress unwanted reflections and ghosting. The result is a high-contrast, bright image - a critical factor when observing faint deep sky objects. The eye relief reaches 22mm, a comfortable value that allows observation without pressing the eye too close to the eyepiece - particularly appreciated by eyeglass wearers and those who spend long hours at the telescope.
Construction and practical features
The eyepiece body is designed with emphasis on practical use in field conditions. It is waterproof and the internal optical chamber is filled with inert gas, which prevents fogging of the lenses from the inside even during dramatic temperature changes - a classic problem familiar to anyone who has taken a telescope from a warm room into a cold winter night. The fold-down eyecup allows comfortable adjustment of eye distance from the eyepiece, both for observation without and with glasses.
Key technical features
- 6-element, 4-group SWA optical design
- Fully multi-coated optical surfaces
- Nitrogen-purged, waterproof body
- Fold-down rubber eyecup
- Filter thread for quick attachment of OIII, UHC or other narrowband filters - no adapter needed
- Parfocal with other eyepieces in the 68° series - no major refocusing when switching focal lengths
Physical parameters
| Parameter |
Value |
| Focal length |
28mm |
| Apparent field of view |
68° |
| Barrel diameter |
2″ |
| Eye relief |
22mm |
| Optical design |
SWA, 6 elements in 4 groups |
| Eyepiece diameter |
69mm |
| Length |
94mm |
| Weight |
515g |
Recommended use
The Explore Scientific N2 28mm 68° eyepiece is ideal as a wide-field eyepiece for deep sky observation on medium to large refractors and reflectors. It performs particularly well with telescopes having a focal length in the range of approximately 800-1500mm, where it delivers a true field of view in the range of tenths of a degree to over one degree - large enough for comfortable location and observation of extended objects such as galactic nebulae, open star clusters, or large planetary bodies. Thanks to the 22mm eye relief, it is equally suitable for observers wearing corrective glasses.
Why choose the Explore Scientific 68° series
The 68° series from Explore Scientific has long been popular precisely because it offers serious optical performance without unnecessary compromises. Multi-layer coatings, hermetic sealing, filter threads, and a parfocal system are features rarely found in cheaper eyepieces. If you are looking for an eyepiece that will serve you faithfully for many years and hold its own against more expensive competition, the N2 series is a very good place to start.
