TS Optics 1.25″ 90° diagonal mirror
Anyone who has ever spent hours at a refractor or Schmidt-Cassegrain telescope with a straight-through eyepiece draw-tube knows how uncomfortable it can be to constantly bend into awkward positions. The TS Optics 1.25″ 90° diagonal mirror solves this problem elegantly - it allows comfortable viewing in an upright position, whether you are observing planets, the Moon or bright star clusters. It is one of those accessories you try once and never want to work without again.
Key features
High reflectivity for minimal light loss
The diagonal mirror offers approximately 91% reflectivity, which ensures that light losses during reflection are kept to a minimum. You will appreciate this especially when observing fainter objects or when working with smaller-aperture telescopes.
All-metal barrels for secure, wobble-free connection
Both connection barrels - the one that fits into the telescope focuser and the one that holds the eyepiece - are made of metal rather than plastic. This guarantees reliable and stable attachment of both the eyepiece and the diagonal itself in the focuser, with no unwanted play or risk of shifting during observation. The standard 1.25″ size ensures full compatibility with the vast majority of modern eyepieces on the market.
Designed for refractors, SCT and Maksutov telescopes
The mirror is designed for refractors, Schmidt-Cassegrain, Maksutov-Cassegrain and similar telescope systems with a rear eyepiece draw-tube. With these instrument types, a diagonal provides a significant ergonomic benefit - without it, the observer would need to look almost straight down toward the ground when viewing objects high above the horizon.
It is important to note that this diagonal mirror is not intended for Newtonian reflectors. Newtonians have a side-mounted focuser and use different types of diagonals or Cass-focusers for comfortable viewing.
Mirror vs. prism - true image orientation
Unlike a prism diagonal, this mirror diagonal does not flip the image left-to-right. For astronomical observation of the night sky this makes no practical difference, but it can be an advantage for occasional terrestrial use when paired with a suitable eyepiece.
Reliable performance in field conditions
The all-metal construction of both barrels contributes to the overall solidity of your setup. When working at night as temperatures drop and dew settles on your equipment, you can be confident that the diagonal will not slip or loosen at a critical moment during your observation session.
About TS Optics
TS Optics (Teleskop Service) is a German company with a long-standing tradition in astronomical optics and accessories. Its products are popular among astronomers across Europe thanks to a sensible price-to-quality ratio, strict production quality control and a wide range of accessories. The 1.25″ 90° diagonal mirror is a direct reflection of this approach - a simple, functional and reliable accessory that does its job without unnecessary complications.
For beginner astronomers it represents an excellent first upgrade to their setup; for experienced observers it makes a practical spare or a convenient addition for a second telescope.
Specifications
| Parameter |
Value |
| Barrel size |
1.25″ |
| Deflection angle |
90° |
| Reflectivity |
approx. 91% |
| Barrel material |
Metal |
| Compatible telescope types |
Refractor, SCT, Maksutov-Cassegrain and similar rear-focuser systems |
| Image orientation |
Mirror image (no left-right flip) |
| Manufacturer |
TS Optics (Teleskop Service), Germany |
