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Explore Scientific 82° 4.5mm LER Waterproof Eyepiece - 1.25"

SKU ES-EPWP8245LE-01
Original price CA$209.99 - Original price CA$209.99
Original price
CA$209.99
CA$209.99 - CA$209.99
Current price CA$209.99
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  • 82° Apparent Field of View
  • 4.5mm High-Magnification Focal Length
  • 15.9mm Long Eye Relief (LER)
  • Argon-Purged Waterproof Construction
  • 1.25" Barrel Diameter
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  • Explore Scientific 82° 4.5mm LER Waterproof Eyepiece - 1.25"

    The Explore Scientific 82° 4.5mm LER eyepiece delivers high-magnification views of the Moon and planets with an immersive, ultra-wide 82° apparent field of view. Its long eye relief of 15.9mm ensures comfortable viewing for all observers, including those who wear glasses. Designed for nights of steady seeing, this 4.5mm eyepiece is built to resolve fine details, from Cassini's Division in Saturn's rings to intricate structures within bright nebulae, all within a waterproof, argon-purged housing for all-weather reliability.

    Immersive 82° Views with High-Contrast EMD Coatings

    This eyepiece provides an ultra-wide 82° apparent field that creates a "spacewalk" sensation, allowing your eye to relax and take in a vast scene. To ensure maximum contrast, the multi-element optical train uses low-dispersion glass with a high refractive index, and every lens is edge-blackened to eliminate internal reflections. Explore Scientific's Enhanced Multi-Layer Deposition (EMD) coatings maximize light transmission, delivering sharp, high-resolution images with crisp definition against a dark sky background.

    A 15.9mm Eye Relief for High-Magnification Comfort

    High-power observing often requires you to hold your eye steady for long periods. The 4.5mm LER eyepiece is engineered with a generous 15.9mm of eye relief, a critical feature for comfort. This extended relief allows eyeglass wearers to see the entire 82° field of view without removing their glasses and provides a more comfortable, less strenuous viewing position for everyone, preventing eye fatigue during detailed planetary observation.

    Argon-Purged Waterproofing for All-Weather Reliability

    Field conditions are unpredictable, but your eyepiece's clarity shouldn't be. Each eyepiece in this series is O-ring sealed and purged with inert argon gas, creating a completely waterproof and internally fog-proof optical housing. This protects the internal EMD coatings from moisture, dust, and fungus, ensuring long-term durability and making the eyepiece easy to clean without fear of contaminants entering the barrel.

    High-Power vs. Mid-Power: The 4.5mm LER in the 82° Series

    The 4.5mm focal length places this eyepiece firmly in the high-magnification category. It excels at splitting tight binary stars and resolving fine detail on planetary surfaces when atmospheric seeing is stable. In contrast, a longer focal length eyepiece from the same 82° series would provide a wider true field of view at lower power, better for framing large deep-sky objects like the Orion Nebula (M42). The trade-off for the 4.5mm's resolving power is its sensitivity to atmospheric turbulence; it demands steady skies to deliver its best views.

  • What kind of viewing comfort does the Explore Scientific 4.5mm LER eyepiece offer for eyeglass wearers?

    The Explore Scientific 4.5mm LER is designed with 15.9mm of long eye relief (LER). This allows observers who wear glasses for astigmatism to see the entire, immersive 82° field of view without having to press their eye against the lens, ensuring a comfortable and complete visual experience.

    On an 8" f/10 SCT, what can I see on Jupiter with the Explore Scientific 4.5mm LER?

    In an 8" f/10 Schmidt-Cassegrain Telescope, this 4.5mm eyepiece yields high magnification ideal for planetary detail. On a night of good seeing, you can expect to resolve Jupiter's main cloud belts, the Great Red Spot (if visible), and potentially smaller ovals and festoons within the zones. The four Galilean moons will appear as distinct, sharp disks.

    How does the waterproof design of the Explore Scientific 4.5mm LER benefit observers?

    The argon-purged and O-ring sealed design makes the eyepiece impervious to internal fogging, even in high-humidity conditions. It also prevents dust, dew, or cleaning fluid from entering the optical housing, protecting the delicate multi-coatings and ensuring the eyepiece performs reliably in any weather.

    What is "averted vision" and how does the 82° field of the Explore Scientific 4.5mm LER help with it?

    Averted vision is the technique of looking slightly to the side of a faint object to place its image on a more light-sensitive part of your retina. The ultra-wide 82° field of view of this eyepiece makes this technique more natural and effective. It provides ample space around the target, allowing you to detect faint details in nebulae or galaxies that are invisible when stared at directly.

    Is the Explore Scientific 4.5mm LER eyepiece good for deep-sky objects?

    Yes, for specific targets. While its high power is not suited for large objects like the Andromeda Galaxy (M31), it is excellent for resolving detail in smaller, brighter deep-sky objects. Use it to split the stars in the Trapezium within the Orion Nebula (M42), examine the structure of planetary nebulae like the Ring Nebula (M57), or resolve individual stars in bright globular clusters like the Hercules Cluster (M13).

    What do the EMD coatings on the Explore Scientific 4.5mm LER eyepiece do?

    The Enhanced Multi-Layer Deposition (EMD) coatings are advanced anti-reflection layers applied to all optical surfaces. Their purpose is to maximize light transmission and minimize scatter, resulting in brighter images, higher contrast, and better resolution. This is especially critical for discerning subtle color variations on planets or faint details at the edge of visibility.

  • GTIN 811803030213
    Focal Length 4.5mm
    Apparent Field of View 82°
    Eye Relief 15.9mm
    Barrel Size 1.25"
    Waterproof Yes, Argon-Purged
    Coatings Fully Multi-Coated (EMD)
  • Explore Scientific Warranty