The Explore Scientific 40mm 68° Series Eyepiece is built for deep sky observers seeking maximum field coverage and comfort. As the longest focal length in the 68° Series, it offers sweeping wide-field views perfect for observing the Andromeda Galaxy, sprawling nebulae, and large star clusters.
Engineered with low-dispersion, high-refractive index glass and coated with EMD (Enhanced Multi-Layer Deposition) coatings, this eyepiece provides exceptional contrast, resolution, and flat field clarity. The 68° apparent field of view offers immersive visual exploration, while parfocal construction ensures a smooth experience when switching between eyepieces.
For rugged environments and long sessions, the eyepiece features a fully waterproof, argon-purged body to prevent fogging and protect against moisture and dust. It’s even submersion-tested at 1 meter for 30 minutes to ensure performance in real-world observing conditions.
With a generous 31mm eye relief and a removable silicone rubber eyecup, this eyepiece delivers all-night comfort—even for eyeglass wearers.
CA Residents: Prop 65 WARNING(S)
🌟 Features & Benefits
- 40mm focal length with wide-angle 68° apparent field for deep sky immersion
- Argon-purged waterproof construction prevents fogging and protects internal optics
- EMD-coated, low-dispersion lenses deliver bright, high-contrast views
- Flat field optical design ensures edge-to-edge clarity
- Parfocal performance maintains consistent focus across Explore eyepieces
- 31mm long eye relief for extended comfort—ideal for eyeglass users
- Flip-down silicone eyecup supports ergonomic viewing
- Submersion-tested for reliable performance in outdoor environments
🎯 Who It’s For
- Deep sky enthusiasts looking to maximize field of view
- Eyeglass wearers needing long eye relief without sacrificing performance
- Users of refractors, Dobsonians, or large SCTs seeking panoramic views
🔭 What You’ll Be Able to See
- Entire Andromeda Galaxy in a single field
- Wide swaths of nebulae, Milky Way star fields, and open clusters
- Broad framing of comets, asterism patterns, and galactic groupings
🎒 What’s Included
- Explore Scientific 40mm 68° Series Waterproof Eyepiece
- Protective end caps
- Soft drawstring pouch
Specs
| Item Number | EPWP6840–01 |
|---|---|
| Focal Length | 40mm |
| Apparent Field | 68° |
| Eye Relief | 31mm |
| Field Stop Diameter | 45.5mm |
| Barrel Size | 2.00" |
| Length | 114.2mm |
| Width | 80.3mm |
| Weight | 35.2 oz / 998g |
| Waterproofing | Argon Purged / O-Ring Sealed |
| Eyecup | Removable Flip-Down Silicone Rubber |
Warranty Information:
This product includes a Limited One-Year USA Warranty, which converts to the Explore STAR Transferable Extended Life of the Product Warranty when registered within 60 days of purchase.
To activate your warranty, register your product at:
www.explorescientific.com/pages/product-registration