Omegon LE Planetary 12.5mm 55° 1.25″ eyepiece
If you are looking for a reliable planetary eyepiece with an excellent price-to-performance ratio, the Omegon LE Planetary series is exactly what you need. The 12.5mm focal length, 1.25″ model delivers high image sharpness and above-average contrast - qualities appreciated by every planetary observer, whether a beginner or an experienced amateur astronomer. Its robust optical design and well-thought-out mechanical construction make this eyepiece an outstanding companion for nights under the stars.
Optical construction
The Omegon LE Planetary 12.5mm consists of seven optical elements arranged in four groups - the same configuration applies to nearly the entire LE Planetary range, with the exception of the 18mm model, which uses three lens groups. All lenses feature blackened edges that suppress stray reflections and scattered light inside the barrel. The glass elements are treated with fully multi-coated (FMC) anti-reflection surfaces, which maximise light transmission and improve contrast - a key parameter when observing planets and the Moon.
Performance in the field
When used with a Newtonian reflector operating at a fast focal ratio, the eyepiece delivers a clean and geometrically accurate image even at the edges of the field of view, with no significant distortion. The 55° apparent field of view provides a comfortable overview when examining surface details on planets or during lunar observations, while keeping the image sharp from centre to edge.
Long eye relief - comfortable for glasses wearers
The 20mm eye relief is one of the most important practical advantages of this eyepiece. It allows observers who wear corrective glasses to view without removing them - the eye remains at a comfortable distance from the eyepiece and the entire field of view is still visible. This is a benefit that is relatively rare among eyepieces in this price category and significantly contributes to overall comfort during long observing sessions.
No kidney beaning
Another welcome technical detail is the suppression of the so-called "kidney bean effect" - the phenomenon where moving your eye towards the edge of the field causes a loss or distortion of the image. With the LE Planetary 12.5mm this disturbing effect does not occur, so you do not need to maintain a precise alignment between your eye and the optical axis of the eyepiece. This is particularly noticeable during more dynamic observing sessions or when working without a motorised mount drive.
The full Omegon LE Planetary range
The Omegon LE Planetary series is available in seven focal lengths, making it easy to build a complete set of eyepieces for different magnifications and observing conditions, with all models sharing the same optical character and consistent image quality.
| Focal length |
Apparent field of view |
Barrel diameter |
| 3mm |
55° |
1.25″ |
| 5mm |
55° |
1.25″ |
| 6mm |
55° |
1.25″ |
| 9mm |
55° |
1.25″ |
| 12.5mm |
55° |
1.25″ |
| 14.5mm |
55° |
1.25″ |
| 18mm |
55° |
1.25″ |
About the Omegon brand
Omegon is a brand designed with the needs of real astronomers in mind. The LE Planetary eyepieces are not a compromise - they are the result of careful selection of optical glass, anti-reflection coatings and mechanical finishing that meets the demands of even more discerning observers. Omegon offers a wide range of accessories for amateur astronomy and places emphasis on ensuring that every product delivers genuine value - whether optics, mounts or accessories. If you are looking for a brand you can trust when building your observing kit, Omegon is a choice that will serve you well for the long term.
