Explore Scientific 68° Series 2" 40mm Waterproof Eyepiece

The 68° Series 40mm is the flagship of the line — maximum focal length, 2" barrel, and lanthanum glass optics delivering the widest, brightest views the series offers. With a 68° field of view at 40mm, you are looking through an expansive window onto the sky. Generous eye relief keeps viewing comfortable even during long sessions. At $289 with argon-purged waterproof construction and premium multi-element optics, it undercuts comparable 2" wide-field eyepieces from other manufacturers.

Key Features

• 2" barrel with 40mm focal length — the longest focal length in the series for maximum sky coverage and brightness
• Multi-element lanthanum glass optics — dense crown, light crown, dense flint, and lanthanum glasses produce sharp, color-corrected images across the full 68° field
• 68° apparent field of view — the widest framing in the 68° series for sweeping panoramic views of the sky
• Generous eye relief for relaxed, comfortable viewing during extended sessions, fully compatible with eyeglasses
• Argon-purged waterproof housing — sealed and fog-proof for dependable all-weather durability
• Enhanced Multi-Layer Deposition (EMD) coatings on all air-to-glass surfaces with edge-blackened elements for contrast

Ideal For

• Wide-field deep-sky observers framing the largest targets — the Pleiades, the full Orion Nebula region, Andromeda Galaxy, and sweeping Milky Way panoramas at their most expansive
• Maximum sky coverage with premium optics — ideal for initial target location, casual scanning, and simply enjoying the breadth of the night sky through quality glass
• 2" focuser owners who want the widest, sharpest views their equipment can deliver at an accessible price compared to ultra-wide-field alternatives