Eyepiece Explore Scientific 82° 18 mm 2" – wide-field astronomical eyepiece

The Explore Scientific 82° 18 mm 2" eyepiece offers an 82-degree apparent field of view designed for 2-inch focusers. With an 18 mm focal length it provides a balance between magnification and wide-field coverage, making it suitable for visual surveying of star fields, nebulae and larger deep-sky objects. The eyepiece is built to deliver comfortable eye relief for extended observing sessions and to maximize the useful field on medium to large telescopes.

Advantages

This wide-field eyepiece gives immersive views with reduced edge distortion across a large apparent field. The 2" barrel size allows full use of the telescope’s native light cone for wider true field of view compared with 1.25" accessories. The 18 mm focal length produces moderate magnification that works well for both deep-sky targets and planetary detail when used on larger apertures. Optics are designed to provide good eye relief and comfortable viewing for users who wear glasses.

Suitable for

• Wide-field observation of star clusters and Milky Way star fields
• Visual surveys of nebulae and extended deep-sky objects
• General-purpose eyepiece for medium to large aperture telescopes
• Observing sessions requiring comfortable eye relief for extended use

Key specifications

• Apparent field of view: 82°
• Focal length: 18 mm
• Barrel diameter: 2 inches
• Design: wide-field eyepiece optimized for visual observing
• Suitable for: medium to large telescopes with 2" focusers

How to use

Insert the 2" barrel securely into the telescope focuser and tighten any retaining thumbscrews or clamps. Start with a low- to medium-power magnification by pairing the 18 mm eyepiece with the telescope’s focal length to assess framing and focus. Adjust the focuser slowly until the image is sharp, then refine using the telescope’s focusing knob. If you wear glasses, set the eye position until the full 82° field is visible; otherwise, bring your eye closer to the eyepiece while maintaining the comfortable eye relief. For best results with extended targets, allow the instrument to reach thermal equilibrium and use appropriate tracking or slow manual adjustments to keep objects centered.

Usage recommendations

Use the eyepiece with a well-collimated optical tube and a stable mount to take full advantage of the wide 82° field. For visual observing of faint nebulae and star fields, observe from a dark site, allow your eyes to dark-adapt, and use averted vision to enhance faint detail. When switching between eyepieces, handle the optic by the barrel and keep the lenses covered when not in use to protect coatings and maintain image quality.