Omegon 90° PRO 1.25″ Amici erecting prism
If you have ever tried to follow a bird on a branch or a ship on the horizon through an astronomical telescope, you know exactly what the problem is - an astronomical telescope produces an image that is flipped both vertically and horizontally. For stargazing this is perfectly acceptable, but when observing terrestrial objects it can be genuinely confusing. The Omegon 90° PRO 1.25″ Amici erecting prism solves this problem elegantly: simply insert it into the focuser in place of your standard diagonal mirror, add an eyepiece, and the image is instantly oriented naturally - exactly as you see it with the naked eye.
How it works
This erecting prism for telescopes operates on the principle of the Amici prism, which uses a series of internal reflections not only to rotate the image but also to mirror it back into its natural orientation. It is therefore a fully functional replacement for a standard diagonal mirror whenever you want to use your telescope for birdwatching, watching ships, observing distant architecture, or wildlife safaris.
The prism is compatible with the following telescope types:
- Refractors
- Maksutov-Cassegrain
- Schmidt-Cassegrain
- Ritchey-Chrétien
Please note: this prism is not intended for Newtonian reflectors, as their optical path does not allow for its use.
Optical quality - FMC coatings on all surfaces
What sets the Omegon PRO apart from cheaper alternatives is the quality of its optical construction. The prism features FMC (Fully Multi-Coated) anti-reflection coatings on every glass-to-air surface. This eliminates unwanted reflections, brightness loss, and contrast reduction - light passes through the prism with minimal losses, giving you an image as bright and contrasty as if no additional element had been placed in the optical path. For demanding observers and astrophotographers, this is a critical parameter that directly affects the overall quality of the final image.
Secure eyepiece retention
The 1.25″ eyepiece barrel is secured by a flat-edge locking ring rather than a single point-contact screw. In practice this means the eyepiece is held by even pressure distributed around its entire circumference, rather than by a single screw that could scratch a chromed or anodised barrel. The eyepiece is held firmly and safely - it will not fall out even when you move the telescope - while the optical surfaces of the eyepiece remain undamaged.
About Omegon PRO
Omegon is an established European brand with a long tradition in astronomical and observational optics, built on careful material selection and rigorous quality control. The PRO range is designed for users who refuse to compromise - whether on light transmission, mechanical durability, or long-term reliability.
The Omegon 90° PRO 1.25″ Amici erecting prism is the ideal choice for anyone who wants to make truly versatile use of their astronomical telescope - both for night-time sky observation and for daytime viewing of nature and distant terrestrial subjects.
Specifications
| Parameter |
Value |
| Type |
Amici erecting prism |
| Angle |
90° |
| Barrel diameter |
1.25″ |
| Optical coatings |
FMC - Fully Multi-Coated (all surfaces) |
| Eyepiece lock |
Flat-edge locking ring |
| Compatible telescopes |
Refractors, Maksutov-Cassegrain, Schmidt-Cassegrain, Ritchey-Chrétien |
| Not compatible with |
Newtonian reflectors |
| Suitable for |
Astronomy, terrestrial observation, birdwatching, wildlife, travel |
