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Explore Scientific  |  SKU: EPWP5240–01

Explore Scientific 52° Series 2" 40mm Waterproof Eyepiece

$179.99 $215.99

Bonus offer: after adding this item to cart, add 3 other eyepieces + the soft-sided case to get it for Free ($49.99 value)

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Explore Scientific 52° Series 2" 40mm Waterproof Eyepiece



  • 40mm Focal Length
  • 52° Apparent Field of View
  • 2" Diameter Barrel
  • Fully EMD Multi-Coated Optics
  • Argon-Filled, Water and Fogproof
  • Slip-Resistant Textured Surface
  • Fold-Down Eyecup


Experience the Majesty of the Night Sky in Wide-Angle

The Explore Scientific 52° Series 2" 40mm Waterproof Eyepiece stands as a testament to the avid deep-sky observer’s quest for expansive cosmic panoramas. With the longest focal length and eye relief in the 52° Series, this eyepiece offers an unparalleled viewing experience, bringing the grandeur of the universe to your eyes.

  • Unmatched 40mm Focal Length: Delivers a sweeping true field of view, making it the eyepiece of choice for observing vast celestial landscapes like the Andromeda Galaxy, the Rosette Nebula, large star clusters, and the ethereal tails of comets.
  • Expansive 52° Apparent Field of View: Immerse yourself in a wide-angle perspective of the cosmos, perfect for deep-sky observation and capturing the faintest limits of your telescope.
  • Superior Optical Clarity: Fully EMD Multi-Coated Optics ensure brilliant light transmission, maximizing contrast and detail even in dimly lit celestial objects.
  • Comfort and Durability: Features the longest eye relief in its series for comfortable extended viewing, alongside argon-filled, waterproof, and fog-proof construction for resilience against the elements. The slip-resistant textured surface and fold-down eyecup add to its ergonomic design.

A Unique Offering Among Giants

As the sole 2.0-inch O.D. eyepiece in the 52° Series, and one of three 40mm eyepieces within Explore Scientific’s broader collection, it occupies a special place for those dedicated to deep-sky observation. Its capabilities are tailored to meet the demands of astronomers seeking to push their telescopes to the observable limits.

Designed for the Art of Averted Vision

Enhance your ability to observe faint celestial wonders through the technique of averted vision. This eyepiece’s design facilitates this subtle art, allowing light from the most elusive objects to fall on the most sensitive part of your retina, revealing details that direct vision might miss.

Embark on a Deep-Sky Adventure

The Explore Scientific 52° Series 2" 40mm Eyepiece is not merely an optical tool; it’s a bridge to the cosmos, inviting you on a journey to explore the depths of space. Whether you’re a seasoned astronomer or a curious stargazer, this eyepiece promises to transform your visual astronomy experience, offering comfort, quality, and exceptional value.

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Explore Scientific 52° Series 2" 40mm Waterproof Eyepiece | EPWP5240–01 | 811803030084

Explore Scientific 52° Series 2" 40mm Waterproof Eyepiece

$179.99 $215.99





Focal Length

40 mm

Focal Ratio


Field of View



Enhanced multi-layer deposition (EMD) coatings

Argon-purged, water and fog proof

27.1mm eye relief

36.3mm field stop diameter

Barrel Size



96.6mm length

61.8mm width


385.5 g | 13.6 oz
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