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Explore Scientific 68° Series 40mm Waterproof Eyepiece

SKU EPWP6840-01
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Original price $519.99 - Original price $519.99
Original price
$519.99 - $519.99
Current price $519.99
Out of stock

Ships To: United States & Canada 🇺🇸 🇨🇦

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We offer a 30 Day Return Policy on most of the products that we carry.

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The vast majority of products that we sell, with a few exceptions, are covered under Warranty.

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Explore Scientific 68 Degree Series 40mm Waterproof Eyepiece - EPWP6840-01

Introducing the Explore Scientific 68° Series 40mm Waterproof Eyepiece.

With cutting-edge computer design, a blend of low dispersion and high refractive index optical glasses, and robust multilayer deposition coatings, Explore Scientific's 68° Series 40mm Argon-Purged Waterproof Eyepiece is meticulously engineered for optical excellence.

These eyepieces are optimized to deliver high contrast, remarkable resolution, and a superior flat field, offering a truly immersive visual experience with their long eye-relief and expansive 68° apparent field of view.

Parfocal across the series, they ensure consistent focus regardless of focal length, and the removable and foldable soft silicone rubber eyecup prioritizes observer comfort, a critical factor when pushing the limits of visual observation.

Protection from the Elements - By purging the eyepiece with Argon gas, the internal optics remain pristine over time.

Argon, being larger in atomic size than Nitrogen, exhibits superior resistance to leakage or diffusion through seals.

Its inert nature prevents adverse chemical reactions with eyepiece components, prolonging their lifespan and safeguarding against chemical interactions with potential contaminants introduced through compromised seals.

Explore Scientific 68° Series Waterproof Eyepiece

Furthermore, Argon's lower heat conductivity buffers rapid temperature changes, ensuring the stability of the optics.

This sealed, dry environment effectively prevents internal fogging and the growth of contaminants like fungus between lens elements.

Cleaning is made easier, and there's no risk of cleaning solution seeping between elements.

To guarantee a flawless seal, each eyepiece undergoes a rigorous 30-minute water submersion test at one meter depth.



  • 68° Apparent Field of View: Immerse yourself in a broad 68-degree apparent field of view, providing a sweeping celestial vista that enhances the observation of celestial objects. This wide field of view promotes relaxation at the eyepiece, allowing for extended periods of comfortable observation.
  • 40mm Focal Length: Striking a balance between magnification and clarity, the 40mm focal length allows for detailed observations of both distant deep-sky wonders and larger celestial bodies like the Moon. Delicate intricacies come alive with astonishing clarity.
  • Advanced Optics: Using advanced computer design, combinations of low dispersion and high refractive index optical glasses, and durable multilayer deposition coatings, this eyepiece is optimized to produce high contrast, high resolution, and superior flat field characteristics. It ensures a top-tier visual experience.
  • Argon-Purged Waterproof Design: The eyepiece body is Argon-purged, creating a sealed, dry environment that is impervious to internal fogging and contaminants. Argon gas, with its larger atomic size compared to Nitrogen, offers superior resistance to leakage through seals, enhancing the longevity of internal components.
  • Enhanced Durability: The robust construction of this eyepiece is engineered to withstand the rigors of regular use and exposure to the elements. Its steadfast reliability and longevity make it an enduring companion for years of astronomical exploration.
  • Removable and Foldable Eyecup: The eyepiece features a removable and foldable soft silicone rubber eyecup for observer comfort. This design element recognizes the critical role of eye comfort, particularly during prolonged observation sessions.
  • Parfocal Design: The 68° Series eyepieces are parfocal, meaning they focus at near the same point regardless of the focal length you select. This ensures consistent focus across the series, enhancing the observer's experience.
  • Water Testing Certification: To guarantee a perfect seal, each eyepiece undergoes a rigorous 30-minute water submersion test at one meter depth. This certification attests to its suitability for various weather conditions, including damp or rainy environments.
  • Edge-Blackened Optics: The optics of this eyepiece undergo edge-blackening, a process that darkens the edges of the lens. This reduces internal reflections and intensifies contrast, resulting in superior image quality, particularly in scenarios with significant variations in brightness.
  • Threaded Barrels for Filters: Equipped with threaded barrels, this eyepiece allows users to attach standard astronomical filters. This feature provides the flexibility to customize the viewing experience, enabling the enhancement of specific colors or the reduction of light pollution according to the observer's preferences and target object.
  • Ample Eye Relief: The eyepiece offers ample eye relief, facilitating extended periods of comfortable observation. This feature is particularly beneficial for eyeglass wearers, allowing them to maintain a full field of view without the need to remove their glasses.
  • Included Accessories: The accessory set accompanying the Explore Scientific 68° Series 40mm Waterproof Eyepiece includes protective eyepiece caps, comfortable soft silicone rubber eyecups, a secure eyepiece pouch/case for storage, and is complemented by a limited 1-year warranty, ensuring heightened peace of mind for users.


                                                                  What's Included:

                                                                  ✓ Explore Scientific 68° Series 40mm  Waterproof Eyepiece

                                                                  ✓ Eyepiece Caps

                                                                  ✓ Soft Silicone Rubber Eyecups

                                                                  ✓ Eyepiece Pouch/Case

                                                                  ✓ Limited 1 year warranty



                                                                          Item Number  EPWP6840–01
                                                                          Focal Length  40mm
                                                                          Length  114.2mm
                                                                          Width  80.3mm
                                                                          Weight  35.2oz; 998g
                                                                          Barrel Size  2.00"
                                                                          Eye Relief  31mm
                                                                          Field Stop Diameter  45.5mm

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