Sky-Watcher secondary mirror for 150/750 Newtonian telescopes
If you own a Newtonian telescope with a 150mm primary mirror and need to replace or supplement its secondary optics, this original Sky-Watcher secondary mirror is exactly what you are looking for. A high-quality secondary mirror is a key element of the entire optical system - even the slightest damage or surface imprecision will immediately affect the resulting image.
Role of the secondary mirror in a Newtonian telescope
The secondary mirror for a Newtonian telescope performs a seemingly simple but absolutely essential function: it reflects the light cone from the primary mirror into the focal plane of the eyepiece. The elliptical shape of the mirror, measuring 71 x 50mm, is carefully designed so that, when properly aligned (collimated), it covers the entire field of view without vignetting while minimizing the central obstruction in the optical path. The surface coating meets the demands of both visual observation and astrophotography.
When is replacement of the secondary mirror necessary?
Replacement of the secondary mirror is typically required after mechanical damage, oxidation of the reflective coating, or when upgrading an existing optical tube. The original Sky-Watcher part guarantees precise compatibility with the spider holder, which significantly simplifies re-collimation. For advanced users who fine-tune their instrument down to the last detail, using original components is the most reliable way to maintain full optical performance.
Compatibility and installation
This mirror is intended primarily for Sky-Watcher 150/750 series telescopes - optical tubes with a focal length of 750mm and a focal ratio of f/5. Before ordering, we recommend verifying the dimensions of your existing secondary mirror and the type of spider holder in your tube to avoid any complications during installation. The replacement itself does not require specialized tools - a standard set of screwdrivers is sufficient, along with patience during the subsequent collimation process.
Key specifications
| Parameter |
Value |
| Mirror shape |
Elliptical |
| Mirror dimensions |
71 x 50mm |
| Compatible telescope type |
Newtonian reflector |
| Compatible series |
Sky-Watcher 150/750 |
| Focal length of tube |
750mm |
| Focal ratio |
f/5 |
| Suitable for |
Visual observation and astrophotography |
Why choose original Sky-Watcher spare parts?
Sky-Watcher is one of the world's most prominent manufacturers of astronomical optics and telescopes. The brand is known for combining an accessible price point with a strong emphasis on optical quality, making it a popular choice among both beginner astronomers and experienced observers. Original Sky-Watcher spare parts are manufactured to the same standards as the components used in new telescopes, so you can be confident that your instrument will retain its original performance parameters.
