Explore Scientific 52° Series 1.25" 20mm Waterproof Eyepiece

The 52° Series 20mm is a go-to general-purpose eyepiece for comfortable, wide views of deep-sky objects. Moderate magnification makes it forgiving and versatile, while argon-purged waterproof construction and EMD coatings provide quality that outlasts cheap kit eyepieces many times over.

Key Features

• Argon-purged waterproof housing — sealed against moisture and fog for reliable performance session after session
• Enhanced Multi-Layer Deposition (EMD) coatings on all air-to-glass surfaces for bright, high-contrast images
• 4-element, 2-group optical design with edge-blackened elements to suppress stray light
• Fold-down silicone rubber eyecup with comfortable eye relief for relaxed viewing, including with eyeglasses
• 1.25" barrel fits standard focusers across all common telescope designs

Ideal For

• Deep-sky enthusiasts framing open clusters, nebulae, and galaxies at magnifications that show structure without dimming the view
• Star party hosts who need a comfortable, easy-to-use eyepiece that visitors can look through without fussing with eye placement
• Kit eyepiece upgrades — a 20mm is a natural replacement that immediately improves contrast and sharpness