Explore Scientific 82° 8.5mm LER Waterproof Eyepiece - 1.25"

High-Magnification 8.5mm Focal Length and 82° Field

The 8.5mm focal length produces high power in most telescopes, perfect for nights of steady seeing when you want to examine the cloud bands of Jupiter, the Cassini Division in Saturn's rings, or the craters of the Moon. Unlike traditional high-power designs, the ultra-wide 82° apparent field creates a "spacewalk" sensation, making the view feel boundless and making it easier to track targets as they drift.

This broad field of view also enhances the use of averted vision, a technique critical for detecting faint details. By looking slightly to the side of an object like the core of the Orion Nebula (M42), you place the image on a more light-sensitive part of your eye, allowing subtle structures to materialize that are invisible with direct vision.

15mm of Long Eye Relief for Viewing Comfort

Many high-power eyepieces suffer from short eye relief, forcing you to press your eye against the lens to see the full field—an impossible task for eyeglass wearers. The Explore Scientific 8.5mm LER eyepiece solves this with a comfortable 15mm of eye relief, allowing you to hold your head at a relaxed distance and see the entire 82° field, with or without glasses.

This focus on comfort is not a luxury; it's a critical component of serious observation. When your eye is relaxed, you can observe for longer periods without fatigue, giving you more time to pick out faint planetary details or resolve close double stars.

A 1.25" Argon-Purged Barrel with EMD Coatings

Built to withstand real-world observing conditions, every eyepiece in the Explore Scientific 82° Series is housed in a sealed, O-ring-lined 1.25" barrel that is purged with inert argon gas. This process makes the eyepiece completely waterproof, preventing internal fogging on dewy nights and protecting the optics from dust, pollen, and fungus for a lifetime of use.

• EMD Coatings: Fully multi-coated with Enhanced Multilayer Deposition (EMD) coatings, the optics maximize light transmission for brighter images and higher contrast.
• Edge-Blackened Optics: The edges of each lens are blackened to minimize internal reflections and stray light, ensuring a dark sky background and making faint objects pop.
• Easy Cleaning: The waterproof design means you can confidently clean the eyepiece without fear of moisture seeping into the housing, simplifying maintenance.

ES 82° 8.5mm vs. a Standard Plössl: The Immersive Difference

While a standard 8.5mm Plössl eyepiece is a functional design, it cannot match the experience delivered by the Explore Scientific 82° LER. A Plössl is often lighter and more affordable, but its optical and ergonomic limitations become clear at high power.

• Field of View: The most dramatic difference is the 82° apparent field of the ES eyepiece versus the restrictive ~50° field of a Plössl. The ES 82° shows you a significantly larger, more context-rich patch of sky at the same magnification.
• Eye Relief: A high-power Plössl typically has very short eye relief, making it uncomfortable for long sessions and unusable for most eyeglass wearers. The 15mm of relief on the ES 8.5mm is a substantial ergonomic upgrade.
• Immersion: The combination of the wide field and comfortable eye relief in the ES 82° eyepiece creates an immersive, engaging view that makes you feel like you are floating in space, rather than just looking through a small porthole.