Eyepiece Tele Vue Plossl 20mm 1.25" with 52° apparent field

The Tele Vue Plossl 20mm 1.25" eyepiece provides medium magnification with a 52° apparent field for visual observation through telescopes that accept 1.25-inch eyepieces. Its Plossl optical design is engineered to deliver good sharpness and contrast across the usable field while keeping a compact, lightweight form factor suitable for handheld handling or installation in a focuser. The eyepiece is intended for general-purpose observing including lunar and planetary detail as well as wider deep-sky views.

Advantages

The Plossl layout balances performance and simplicity, offering a clear image with reduced aberrations toward the field edge compared with simpler eyepiece designs. The 20mm focal length yields moderate magnification that works well with a wide range of telescope focal lengths, and the 52° apparent field gives a comfortable viewing area without requiring an oversized eyepiece barrel. Its compact size and standard 1.25" barrel make it compatible with many eyepiece holders and accessories.

Suitable for

• Visual observation of the Moon and planets at medium magnification
• Wide-field views of star clusters and brighter deep-sky objects
• Portable observing sessions where compact, easy-to-change eyepieces are preferred
• Use in focusers and diagonal holders designed for 1.25" eyepieces

Key specifications

• Focal length: 20 mm
• Apparent field of view: 52°
• Barrel diameter: 1.25 inches (standard)
• Optical design: Plossl (multi-element symmetric configuration)
• Form factor: compact, lightweight eyepiece suitable for visual use

How to use

Insert the 1.25" barrel into the telescope focuser or diagonal and secure it with the focuser thumbscrew or clamp. Achieve focus by adjusting the focuser while observing a high-contrast object such as the Moon or a bright star, then fine-tune for comfortable eye relief and sharpness. For best results, pair the eyepiece with a telescope that provides a medium eyepiece magnification with this focal length; avoid excessive magnification beyond the telescope’s practical limits to maintain image quality.

Usage recommendations

Use the eyepiece with appropriate dew protection in humid conditions and keep optical surfaces clean using recommended lens-cleaning materials. When switching eyepieces, support the telescope optical tube to prevent strain on the focuser. For improved contrast on planetary targets, observe from a stable mount and allow the telescope to reach thermal equilibrium.