Omegon Flatfield ED 5mm 60° 1.25″ eyepiece
If you are looking for an eyepiece that combines a wide field of view, outstanding sharpness and a truly flat image all the way to the edges, the Omegon Flatfield ED 5mm 1.25″ eyepiece is exactly what you need. It is designed to eliminate one of the most common shortcomings of cheaper eyepieces - distortion and blurring of objects as they move towards the edge of the field of view. The result is a clean, sharp and high-contrast image across the entire 60° field.
ED glass optics and multi-layer coatings
The six-element optical design uses ED glass (extra-low dispersion glass), which effectively suppresses chromatic aberration. This means that when observing planets, the Moon or star clusters, you will not see unwanted colour fringing around objects. ED glass also contributes to high contrast, and image sharpness is maintained even at higher magnifications. All optical surfaces feature multi-layer FMC anti-reflection coatings that minimise reflections and light scatter, ensuring maximum brightness and clarity of the image.
Comfortable viewing - even with glasses
The eyepiece has an eye relief of 16mm, so observers wearing glasses can comfortably view the entire field of view without having to remove their corrective lenses. It also includes a solid threaded eyecup that simply screws onto the eyepiece body - it prevents stray light from entering and increases comfort during longer observing sessions. The large 21mm lens diameter contributes to comfortable viewing even at high magnification, when the exit pupil is at its smallest.
Part of a complete Flatfield ED series
The Omegon Flatfield ED series is available in a full range of focal lengths - 25mm, 18mm, 15mm, 8mm and 5mm - making it easy to build a complete set of eyepieces with consistent optical quality. The 5mm focal length eyepiece is ideal for detailed observation of planets and the Moon at high magnification, while retaining all the advantages of the Flatfield ED line. Even with Newtonian telescopes at f/5, the edges of the field of view remain well defined and free of significant aberrations.
Technical specifications
| Parameter |
Value |
| Focal length |
5mm |
| Barrel diameter |
1.25″ |
| Apparent field of view |
60° |
| Eye relief |
16mm |
| Lens diameter |
21mm |
| Optical elements |
6 elements |
| Glass type |
ED (extra-low dispersion) |
| Coatings |
FMC multi-layer anti-reflection |
| Eyecup |
Threaded, fixed |
Why choose the Omegon Flatfield ED 5mm?
Omegon is a brand created by astronomers for astronomers, with an emphasis on build quality and optical performance at an accessible price. The Flatfield ED series offers optical properties that were previously the preserve of significantly more expensive eyepieces - a flat field, ED glass and multi-layer anti-reflection coatings in one compact package.
Thanks to the wide range of available focal lengths and accessories, every observer can easily put together a set tailored precisely to their needs, whether they are observing planets, double stars or extended nebulae. The Omegon Flatfield ED 5mm is a reliable choice for anyone who does not want to compromise on image quality.
The Omegon Flatfield ED series at a glance
- Flat, sharp image across the entire 60° field of view
- ED glass effectively eliminates chromatic aberration
- FMC coatings for maximum light transmission and contrast
- 16mm eye relief - comfortable viewing with or without glasses
- Threaded eyecup blocks stray light during extended sessions
- Available in focal lengths: 5mm, 8mm, 15mm, 18mm and 25mm
- Compatible with Newtonian telescopes at f/5 and above
