Explore Scientific 52° LER 3mm AR Eyepiece – 1.25"
Push your telescope to high magnifications with the Explore Scientific 52° LER 3mm AR Eyepiece, designed for observers seeking detailed views of the Moon, planets and close double stars. Combining a short 3mm focal length with a 52° apparent field of view, this eyepiece is suited to high-power observing when atmospheric conditions and telescope optics allow you to extract fine details.
High-Power Lunar and Planetary Observation
The 3mm focal length delivers very high magnification, making this eyepiece particularly useful for examining lunar craters, mountain ranges, planetary cloud bands and Saturn's rings. It can also help split close double stars when your telescope has sufficient resolution and the atmosphere is steady.
At these magnifications, image quality depends heavily on atmospheric seeing, telescope collimation and thermal equilibrium. The 3mm eyepiece is therefore best used on nights when the air is stable enough to support high-power observation.
Comfortable Viewing with Long Eye Relief
The Explore Scientific 52° LER series is designed to provide generous eye relief and a comfortable viewing position. Its foldable rubber eyecup helps observers establish a consistent eye position, making extended observing sessions more comfortable. The long-eye-relief design is especially useful for eyeglass wearers, although comfort with glasses depends on the effective eye relief of the specific focal-length model.
High-Contrast, Fully Multi-Coated Optics
Explore Scientific's patented EMD (Enhanced Multi-Layer Deposition) coatings are designed to maximise light transmission and contrast while reducing unwanted reflections and ghosting. Blackened lens edges further help control stray light, supporting clean, well-defined images of bright lunar and planetary targets against a darker background.
The flat-field optical design is engineered to maintain good image sharpness across the field, including when used with fast telescope optics.
Sealed and Argon-Purged Construction
Built for regular use in the field, the eyepiece features argon-purged, sealed construction to help prevent internal fogging and protect the optics from moisture and dust. Its durable metal housing, stainless-steel barrel and tapered safety profile provide practical benefits during setup and observing. The eyepiece is also designed to be parfocal with other eyepieces in the 52° LER series, reducing the amount of refocusing needed when switching between compatible models.
Key Features
Focal length: 3mm
Apparent field of view: 52°
Barrel diameter: 1.25 inches (31.7mm)
Optical coatings: EMD fully multi-coated optics
Stray-light control: Blackened lens edges
Construction: Argon-purged and sealed
Eyecup: Foldable rubber eyecup
Barrel: Stainless steel with tapered safety profile
Design: Flat-field optics
Compatibility: Standard 1.25-inch telescope focusers
Ideal For
Detailed lunar observation
High-magnification planetary viewing
Splitting close double stars
High-resolution observing with telescopes capable of supporting very high magnifications
The Explore Scientific 52° LER 3mm AR is a specialised high-power eyepiece for observers who want to explore fine celestial details. Its combination of contrast-enhancing coatings, sealed construction and practical viewing features makes it a useful addition to a planetary observer's eyepiece collection.
Note: Magnification is calculated by dividing your telescope's focal length by 3mm. Very high magnifications are not always advantageous; the best results depend on aperture, optical quality and atmospheric seeing.