Discover fine lunar and planetary details with the Explore Scientific 52° LER 4.5mm AR Eyepiece, a high-magnification eyepiece designed for sharp views, excellent contrast and comfortable observing. With its 4.5mm focal length and 52° apparent field of view, it is an excellent choice for observing the Moon, planets, double stars and compact deep-sky objects under favourable atmospheric conditions.
High-Magnification Performance
The short 4.5mm focal length delivers high magnification with a wide range of telescopes, making it particularly useful for examining lunar craters, planetary cloud bands, Saturn's rings and close double stars. It can also reveal bright, compact deep-sky objects, such as planetary nebulae and globular clusters, when observing conditions permit.
Comfortable Long Eye Relief
Designed with approximately 15mm of eye relief, the 52° LER series offers a comfortable viewing experience, including for many observers who wear glasses. Its fold-down rubber eyecup makes it easy to adjust your viewing position and helps provide a secure, comfortable fit during extended observing sessions.
High-Contrast, Fully Multi-Coated Optics
The eyepiece features Explore Scientific's proprietary EMD (Enhanced Multi-Layer Deposition) coatings on all air-to-glass surfaces to improve light transmission and contrast while minimising unwanted reflections and ghosting. Blackened lens edges further suppress stray light, helping deliver clean, well-defined views. Its flat-field optical design is engineered to maintain good image sharpness across the field, including when used with fast telescopes.
Sealed, Argon-Purged Construction
Built for dependable performance in the field, this eyepiece features argon-purged, O-ring-sealed construction to resist internal fogging and protect the optics against moisture and dust. Its durable metal housing and stainless-steel barrel are designed for long-term use, while the tapered barrel safety profile helps prevent accidental slipping when used with compatible accessories.
Key Features
Focal length: 4.5mm
Apparent field of view: 52°
Barrel diameter: 1.25 inches (31.7mm)
Eye relief: Approximately 15mm
Optical design: 6 elements in 3 groups
Optical coatings: Fully multi-coated EMD optics
Internal reflection control: Blackened lens edges
Construction: Argon-purged and O-ring sealed
Eyecup: Fold-down rubber eyecup
Waterproof design: Yes
Weight: Approximately 185g
Recommended for: High-magnification lunar and planetary observation, double-star splitting and detailed viewing of compact deep-sky objects.
The Explore Scientific 52° LER 4.5mm AR is a practical choice for astronomers seeking high-power performance, comfortable eye relief and reliable optical construction in a compact 1.25-inch eyepiece.
Note: Actual magnification depends on your telescope's focal length. The useful magnification is also limited by atmospheric seeing, telescope collimation and thermal equilibrium.