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Explore Scientific 52° Series 20mm Waterproof Eyepiece

SKU EPWP5220-01
Original price $0.00 - Original price $0.00
Original price $0.00
$119.99 - $119.99
Current price $119.99
In stock

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Explore Scientific 52 Degree Series 20mm Waterproof Eyepiece - EPWP5220-01

Presenting the Explore Scientific 52° Series 20mm Waterproof Eyepiece, a versatile tool that's widely regarded as the ideal mid-range focal length for amateur telescopes.

When paired with the ED127 at f7.5, it yields a generous 1-degree true field of view, making it perfect for pursuits like the Messier Marathon or navigating the Herschel Catalog.

Its compact size and adaptable magnification range also make it a smart choice for most binoviewers.

Experience the epitome of comfort, quality, and value with Explore Scientific 52° Series 20mm Waterproof Eyepieces.

These flat-field, multi-element oculars from the 52° Series have a remarkable apparent field of view of 52 degrees, providing exceptional value in a premium eyepiece.

They offer a level of quality and value that rivals similarly priced Plossl eyepieces.

One notable advantage of these eyepieces is their ability to deliver excellent contrast and facilitate a technique known as averted vision.

This technique allows you to observe objects not by directly focusing on them, but by slightly diverting your gaze to either side.

This proves particularly beneficial when observing faint objects, as it places the image on a more light-sensitive part of your eye, enabling you to perceive fainter details..



  • 52° Apparent Field of View: The Explore Scientific 52° Series 20mm Waterproof Eyepiece provides a generous 52-degree apparent field of view. This wide field of view allows for immersive observations of celestial objects, enabling you to capture more of the night sky in a single glance.
  • 20mm Focal Length: With a focal length of 20mm, this eyepiece offers a versatile magnification level for a wide range of astronomical observations. This focal length strikes a balance between providing a comfortable view of extended objects like star clusters and galaxies while still allowing for detailed views of planets and lunar features.
  • EMD (Enhanced Multi-Layer Deposition): The Explore Scientific 52° Series Eyepiece features EMD coatings, which refer to Enhanced Multi-Layer Deposition. This specialized coating process enhances light transmission and reduces internal reflections. As a result, users can expect sharper, higher contrast images with improved color fidelity.
  • Waterproof - O-Ring Sealed Argon Gas Purged: This eyepiece is designed to withstand the elements with its waterproof construction. It is equipped with O-ring seals that create a tight, moisture-resistant seal, preventing water, dust, and debris from entering the eyepiece. In addition, it is filled with argon gas, which further enhances its resistance to internal fogging and moisture-related damage.
  • Rigorous Water Testing: The Explore Scientific 52° Series20mm Waterproof Eyepiece has undergone rigorous testing to ensure its waterproof capabilities. It has been submerged under one meter of water for a duration of 30 minutes without experiencing any degradation in performance. This makes it suitable for use in a variety of weather conditions, including damp or rainy environments.
  • Edge Blackened: The eyepiece features edge-blackened optics. This process involves darkening the edges of the lens elements to reduce internal reflections and improve contrast. By minimizing stray light, edge blackening enhances the overall image quality, particularly in situations with high contrast between bright and dark areas.
  • High-Quality Optics: The Explore Scientific 52° Series Eyepiece is crafted with precision optics that are designed to deliver high-quality views of celestial objects. The lenses are manufactured to exacting standards, and their optical surfaces are polished to minimize aberrations and maximize light transmission.
  • Durable Construction: Built with durability in mind, this eyepiece features a rugged construction that can withstand the demands of outdoor use. Its robust design ensures that it can endure transportation, handling, and exposure to various environmental conditions without compromising its optical performance.
  • Threaded Barrels for Filters: The eyepiece is equipped with threaded barrels, allowing users to attach standard astronomical filters. This feature enables customization of the viewing experience, allowing for the enhancement of specific colors or the reduction of light pollution, depending on the observer's preferences and the target object.
  • Comfortable Eye Relief: The Explore Scientific 52° Series 20mm Waterproof Eyepiece provides comfortable eye relief, allowing users to observe for extended periods without experiencing eye strain. This feature is particularly valuable for eyeglass wearers, as it ensures that they can still achieve a full field of view without having to remove their glasses.
  • Included Accessories: The accessory ensemble accompanying the Explore Scientific 52° Series 20mm 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, providing users with enhanced peace of mind.

                                                                Explore Scientific 52° Series Eyepieces Highlight Video:

                                                                Explore Scientific Eyepiece Guide Video:

                                                                What's Included:

                                                                ✓ Explore Scientific 52° Series 20mm Waterproof Eyepiece

                                                                ✓ Eyepiece Caps

                                                                ✓ Soft Silicone Rubber Eyecups

                                                                ✓ Eyepiece Pouch/Case

                                                                ✓ Limited 1 year warranty



                                                                Item Number  EPWP5220–01
                                                                Focal Length  20mm
                                                                Length  71mm
                                                                Weight  43mm
                                                                Weight  181.4 grams; 6.4 oz.
                                                                Barrel Size/Type  1.25" O.D. / Double Taper
                                                                Eye Relief  15mm
                                                                Field Stop Diameter  18.2mm
                                                                Coatings  EMD (Enhanced Multi-Layer Deposition) on all lens-to-air surfaces
                                                                Lens Elements/ Groups  5 Elements in 3 Groups; Edge Blackened
                                                                Filter Thread  Fits Standard 1.25-inch Dia. Thread in Filters (1.125-inches x 42 TPI)
                                                                Waterproof  O-Ring Sealed Argon Gas Purged; Tested Under 1 Meter of Water for 30 Minutes
                                                                Eyecup  Removable Flip-Down Style Soft Silicone Rubber
                                                                Lens Caps  Slide-on Top and Bottom
                                                                Materials  Optical Glass; Aluminum; Steel; Silicone Rubber
                                                                Markings  Laser Engraved: Focal Length; Series; Serial Number; Brand

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