Explore Scientific 52° Series 1.25" 25mm Waterproof Eyepiece

The 52° Series 25mm provides the widest field of view available in a 1.25" barrel at this focal length, framing large deep-sky targets with comfortable eye relief and low magnification. Argon-purged waterproof construction means it handles years of dew-soaked sessions without complaint.

Key Features

• Argon-purged waterproof housing — sealed and fog-proof for reliable observing in humidity, dew, and temperature swings
• Enhanced Multi-Layer Deposition (EMD) coatings on all air-to-glass surfaces maximize brightness across the field
• 4-element, 2-group optical design with edge-blackened elements to suppress internal reflections
• Fold-down silicone rubber eyecup with generous eye relief for comfortable extended viewing, including with eyeglasses
• 1.25" barrel fits standard focusers on refractors, reflectors, and catadioptric telescopes

Ideal For

• Deep-sky observers sweeping through open star clusters, large nebulae, and galaxy groups at low power where brightness matters
• Finder-eyepiece pairing — a low-power 25mm makes an excellent locator eyepiece for centering targets before swapping to higher magnification
• Wide-field scanning of the Milky Way, rich star fields, and extended objects like the Veil Nebula or North America Nebula