Explore Scientific 100° 25mm Waterproof Eyepiece - 2"

The 100° Spacewalk Experience at 25mm

With an apparent field so vast, the boundary of the eyepiece seems to dissolve, leaving you suspended in space. This 100° field makes locating objects effortless and allows them to drift through the view for long periods in non-driven telescopes like Dobsonians, minimizing the need for constant adjustments. This expansive view also enhances the use of averted vision, making it easier to detect faint details in nebulae and galaxies by placing them on the more light-sensitive parts of your retina.

Argon-Purged and Waterproof to 1 Meter

Engineered for durability in all observing conditions, each eyepiece is internally sealed and purged with dry argon gas. This inert gas prevents internal fogging during nights with heavy dew and protects the internal multi-coatings from moisture-induced degradation over the eyepiece's lifetime. To ensure field-readiness, every eyepiece is tested for integrity by being submerged in 1 meter of water for 30 minutes, guaranteeing a completely waterproof seal against the elements.

• Maximum Contrast: All internal lens elements are fully multi-coated and edge-blackened to eliminate stray light, ensuring a dark background sky and maximizing image contrast.
• Dew-Proof Operation: The sealed optical train means you can move from a warm house to a cold outdoor environment without worrying about condensation forming between the lenses.

100° vs. 50° AFOV: Framing the Orion Nebula (M42)

While a standard 25mm eyepiece with a 50° field provides a sharp, useful view, its limitations become apparent on large targets. A typical 50° eyepiece might frame the core of the Orion Nebula (M42), showing the Trapezium stars clearly, but the sprawling outer wings of the nebula are cut off. The trade-off for this narrower view is typically lower cost and lighter weight.

In contrast, the Explore Scientific 100° 25mm eyepiece, at the exact same magnification, contains the entire M42 complex in a single, immersive view. You see the Trapezium, the intricate gas clouds, and the faint outer loops all at once, set against a vast backdrop of surrounding stars. For large objects like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000), this capability is not just an incremental improvement; it's a completely different way of observing.