TS Optics 90° dielectric diagonal mirror 1.25″
Looking for a diagonal mirror that won't compromise your observing experience? The TS Optics 90° dielectric diagonal mirror for 1.25″ eyepiece output is a choice appreciated by beginning astronomers and experienced stargazers alike. Thanks to precisely crafted optics and a robust all-metal construction, this accessory delivers performance that rivals the best products on the market - at a very reasonable price.
Optical performance
Dielectric diagonal mirror with 99% reflectivity ensures that virtually all the light captured by the telescope's primary optics reaches your eyepiece. Compared to conventional mirrors with aluminium or silver coatings, which typically achieve 88-95% reflectivity, dielectric coatings noticeably improve both contrast and image brightness - especially when observing faint deep-sky objects or fine details on planets.
The mirror surface accuracy reaches 1/12λ (lambda), a parameter worthy of the premium segment. Such a flat reflective surface introduces no disturbing aberrations or distortions into the image. BK7 optical glass provides excellent homogeneity and transparency of the substrate on which the dielectric layers are applied.
Build quality and compatibility
The mirror body is made entirely of metal, which brings several advantages:
- Excellent resistance to mechanical damage
- Stable eyepiece retention without unwanted flex
- Long service life even with daily use
Both the inlet and outlet are standardised to 1.25″ diameter, so the mirror works seamlessly with the vast majority of refractors, Newtonians in Coudé focus configuration, or catadioptric telescopes with a suitable focuser.
The 90° angle is the most comfortable choice for observing objects at altitude above the horizon - you look through the eyepiece approximately horizontally or slightly downward, which significantly reduces fatigue during longer observing sessions.
Versatile use
The mirror is suitable both for visual observation and as a foundation for basic astrophotography with short exposures. High reflectivity and optical precision are key here for preserving image quality across the entire cross-section of the light cone.
About TS Optics
TS Optics (Teleskop-Service) is a German brand with a long tradition in astronomical optics. Every product is developed based on the requirements of real astronomers, with emphasis on manufacturing precision, careful quality control, and real-world usability in the field. TS Optics diagonal mirrors are popular throughout Europe precisely because they offer professional optical parameters in an affordable package, without unnecessary compromises.
Whether you are looking for a reliable upgrade for your telescope or choosing your first diagonal mirror with truly good specifications, this choice will not disappoint.
Technical specifications
| Parameter |
Value |
| Diagonal angle |
90° |
| Inlet / outlet diameter |
1.25″ |
| Reflectivity |
99% |
| Surface accuracy |
1/12λ |
| Optical glass |
BK7 |
| Coating type |
Dielectric |
| Body material |
All-metal |
| Brand |
TS Optics (Teleskop-Service, Germany) |
