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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Explore Scientific 100° 20mm Waterproof Eyepiece - 2"
Explore Scientific 100° 20mm Waterproof Eyepiece - 2"
Explore Scientific 100° 20mm Waterproof Eyepiece - 2"

Explore Scientific 100° 20mm Waterproof Eyepiece - 2"

by Explore Scientific
SKU ES-EPWP10020-01
$499.99 - $499.99
$499.99
$499.99 - $499.99
$499.99
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  • Expansive Apparent Field of View
  • 2-inch Diameter Barrel
  • Waterproof and Fog-Proof Construction
  • Argon-Purged and Sealed Optical Housing
  • Fully Multi-Coated and Edge-Blackened Optics
1 in stock
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Explore Scientific 100° 20mm Waterproof Eyepiece - 2"

    The Explore Scientific 100° 20mm Waterproof Eyepiece delivers an immense 100° apparent field of view in a 2-inch barrel format. This 20mm eyepiece is engineered to create a panoramic, immersive viewing experience that relaxes the eye, allowing you to study subtle details for extended periods. To ensure maximum durability and contrast, each eyepiece is fully sealed, argon-purged, and tested to be waterproof at a depth of 1 meter for 30 minutes.

    The 100° Panoramic Viewing Experience

    With an apparent field of view of 100°, this eyepiece provides a "spacewalk" experience, where the boundary of the eyepiece seems to dissolve. This ultra-wide perspective is not just for dramatic effect; it relaxes your eye, allowing you to comfortably scan large star fields and take in the full context of large deep-sky objects without constantly moving the telescope.

    • Maximum Contrast: The optics are fully multi-coated and edge-blackened to eliminate internal reflections and light scatter, producing a dark sky background and making faint details pop.
    • Relaxed Viewing: The expansive field helps you forget you're looking through an eyepiece, reducing eye strain during long observing sessions of objects like the Veil Nebula complex or the Andromeda Galaxy (M31).
    • Eye Placement: A trade-off of such a wide field is that eye placement can be more critical than in narrow-field designs. You may need to move your eye slightly to take in the extreme edges of the field.

    All-Weather Reliability: Waterproof to 1 Meter

    The Explore Scientific 100° series eyepieces are built to withstand challenging field conditions. Each unit is hermetically sealed and purged with inert argon gas, which is more effective than nitrogen at preventing internal fogging over a wider temperature range. This process also protects the internal coatings from moisture, fungus, and fine dust, maximizing their lifespan.

    To guarantee this seal, every eyepiece is factory-tested by being submerged in 1 meter of water for 30 minutes. This ensures your investment is protected from unexpected dew, humidity, or even accidental exposure to rain, providing peace of mind for any observing environment.

  • How does the 20mm focal length of the Explore Scientific 100° eyepiece perform on globular clusters like M13 in an f/10 SCT?

    In a typical 8-inch or 11-inch f/10 Schmidt-Cassegrain Telescope, a 20mm focal length provides medium-to-low magnification (around 100x-140x). This is ideal for framing the entirety of large globular clusters like the Hercules Cluster (M13) or Omega Centauri within the immersive 100° field, showing the cluster against a dark, expansive background.

    What is the benefit of the 100° field when framing large nebulae like the North American Nebula (NGC 7000)?

    The primary benefit is context. Large emission nebulae often span several degrees of the sky. The ultra-wide 100° field of the Explore Scientific 20mm eyepiece allows you to see these objects in their entirety, especially when paired with a rich-field refractor. You can trace the full "coastline" of NGC 7000 or the sprawling arms of the Orion Nebula (M42) in a single view.

    Why is the Explore Scientific 100° 20mm eyepiece purged with argon instead of nitrogen?

    Argon gas molecules are larger than nitrogen molecules, making them less prone to escaping through the eyepiece's seals over time. This provides a more stable, long-term waterproof and fog-proof solution, ensuring the internal optics remain pristine for the life of the eyepiece.

    Is the 2-inch barrel on the Explore Scientific 100° 20mm necessary for the wide field?

    Yes, a 2-inch barrel is essential. The physical diameter of a 1.25-inch barrel would act as a restrictive aperture, making it impossible to deliver such a wide, well-illuminated 100° field of view to the observer's eye without significant vignetting (darkening at the edges).

    What does it mean that the Explore Scientific 100° 20mm is tested to be waterproof for 30 minutes at 1 meter?

    This is a rigorous durability standard. It means the eyepiece's seals are robust enough to prevent any water intrusion even when fully submerged. For an astronomer, this translates to complete protection against heavy dew, high humidity, and accidental splashes or rain, preventing internal fogging or damage.

    Will I need to move my head around to see the whole 100° field in the Explore Scientific 20mm eyepiece?

    For some observers, yes. Achieving a comfortable view of the entire 100° field at once can depend on your individual eye placement and whether you wear glasses. It is common with ultra-wide eyepieces to slightly shift your eye position to fully appreciate details at the very edge of the field stop.

  • Explore Scientific Warranty