Explore Scientific 82° 18mm Waterproof Eyepiece - 2"

The 18mm Focal Length: An 82° Window on Globular Clusters

The 18mm focal length provides a versatile medium-high magnification, ideal for examining the bright cores of comets, planetary nebulae like the Ring Nebula (M57), and resolving individual stars in globular clusters like the Hercules Cluster (M13). The optical design uses low-dispersion and high-refractive-index glasses with Enhanced Multilayer Deposition (EMD) coatings to produce sharp, high-contrast images across its flat 82° field.

The 82° Immersion Experience: Long Eye Relief for Relaxed Observing

An 82° apparent field of view creates a true full-immersion experience, allowing your eye to relax and take in the entire scene. This wide vista makes it easier to use averted vision—looking slightly to the side of a faint object—to detect subtle details in galactic arms or faint nebulosity. The generous eye relief ensures a comfortable viewing position, even for extended periods at the eyepiece.

Rugged 2-Inch Design: Argon-Purged and Waterproof for Field Use

Built for years of use under the stars, this eyepiece features a completely sealed, waterproof optical housing purged with inert argon gas. This process prevents internal fogging in damp conditions and protects the EMD coatings from fungus and moisture, ensuring pristine views for the life of the eyepiece. All internal surfaces are blackened, and lens edges are darkened to eliminate internal reflections and maximize image contrast.

Explore Scientific 18mm 82° vs. a Standard Plössl Eyepiece

While a standard Plössl eyepiece is a capable and affordable design, the Explore Scientific 82° offers a fundamentally different observing experience. A Plössl's field is typically limited to around 50°, whereas this eyepiece's 82° field reveals a significantly larger patch of sky at the same magnification.

• Contextual Framing: The wider 82° field allows you to see objects within their larger celestial neighborhood, making star-hopping and target acquisition more intuitive.
• Enhanced Contrast: The advanced EMD coatings and superior internal baffling of the Explore Scientific 82° design deliver a darker sky background and higher contrast compared to eyepieces with standard coatings.
• Trade-Offs: The primary advantages of a Plössl are its smaller size, lighter weight, and lower cost. However, for an immersive, high-contrast view, the 82° design is superior.