Astronomical Reflective Telescope Secondary Mirror Key benefits Restores and maintains optical performance: the secondary mirror redirects light precisely so your telescope delivers clear, contrast images. Protects the primary mirror: an applied protective film prevents scratches on the main mirror from light contact during handling and installation. Reliable fit and optical quality: tight dimensional tolerance and measured surface accuracy reduce alignment issues and preserve image quality. Features and specifications Function: Secondary mirror for reflective astronomical telescopes. Optical type: Spherical mirror. Coating: Aluminized reflective surface for strong reflectivity. Protective layer: Film applied to prevent scratches on the primary mirror under light touch. Dimension tolerance: ±0.5 mm to help ensure proper fit in the optical assembly. Surface accuracy: PV 1/4–1/6 λ, providing low wavefront error for good optical performance. Why this product matters Compatibility and fit: The ±0.5 mm tolerance helps the mirror seat correctly in standard secondary mounts, reducing the need for adjustment and minimizing tilt or decenter errors. Image fidelity: Surface accuracy of PV 1/4–1/6 λ keeps aberrations low, supporting sharp views for visual observing and reasonable performance for imaging. Durability in handling: The protective film reduces the risk of accidental scratches to the primary mirror during routine maintenance, transport, or replacement. Typical applications Replacing a worn or damaged secondary mirror on a backyard reflecting telescope to restore viewing performance. Upgrading or refurbishing an older reflector where the secondary has lost reflectivity or surface quality. Use in amateur observatory setups or educational telescopes where reliable, repeatable performance and easier handling are needed. Installation notes Designed for use in reflective telescope systems requiring a spherical secondary mirror. Verify mechanical dimensions and mount type before installation. Handle carefully; the protective film is intended to guard against light contact but is not a substitute for safe handling and proper cleaning procedures. This secondary mirror supplies the core optical function required in reflective telescopes while offering protective and manufacturing tolerances that aid fit, handling, and image quality.