Skyoptikst 114mm 900mm Newtonian Primary Mirror

The Skyoptikst 114 mm diameter, 900 mm focal length Newtonian primary mirror is a high-precision aluminum-coated optics component engineered for amateur and semi-pro astronomical reflectors.

Designed as the optical heart of a small Newtonian telescope, this primary mirror combines a long focal length with a compact 114 mm aperture to deliver crisp, contrast-rich images for planetary, lunar and bright deep-sky observation. The mirror is polished to a 1/10 λ surface accuracy, then finished with an enhanced aluminum coating and protective overcoat that yields strong reflectance across 400–950 nm wavelengths.

How will this mirror affect my telescope's image quality?

A 1/10 λ surface accuracy minimizes wavefront errors, improving sharpness and contrast so stars appear tighter and planets show finer detail. The mirror's enhanced aluminum coating boosts light return across visible and near-infrared bands for brighter views.

• 1/10 λ surface accuracy reduces optical aberrations.
• 92% reflectance across 400–950 nm increases overall brightness.
• 900 mm focal length provides moderate focal ratio suitable for high-resolution targets.
• Enhanced protective coating resists oxidation and handling wear.

Will it fit my Newtonian build and how do I mount it?

The mirror's 114 mm clear aperture and specified focal length make it compatible with many small Newtonian tube assemblies and DIY builds. Mounting typically requires a cell sized for a 114 mm mirror and a collimation-friendly support system to maintain alignment.

• Caliber: 114 mm — standard for compact Newtonians.
• Focal length: 900 mm — yields approximately f/7.9 focal ratio.
• Use a padded mirror cell and three-point support to prevent stress.
• Finish collimation with a laser or Cheshire tool after installation.

What spectral performance and coatings are provided?

The mirror carries an enhanced aluminum reflective layer plus a protective overcoat to maintain performance over time. Specified reflectance is about 92% between 400 and 950 nm, ensuring efficient throughput for visual observing and many imaging sensors.

• Enhanced aluminum coating for improved visible/near-IR response.
• Protective overcoat reduces tarnish and eases cleaning.
• 92% reflectance across critical observational bands (400–950 nm).
• Coating profile favors contrast and color neutrality for visual work.

How durable and serviceable is the mirror?

The protective coating extends usable life under normal use and storage, but like all optical surfaces it benefits from careful handling and occasional gentle cleaning. Avoid abrasive cleaners and use recommended optical solutions for maintenance.

• Protective overcoat resists oxidation and minor surface contaminants.
• Handle by the cell or perimeter to prevent fingerprints on the optical surface.
• Clean only with compressed air, distilled water, or approved optical fluids if necessary.
• Store in a padded, dry environment to preserve coating life.

Who is this for: This Skyoptikst primary mirror is aimed at backyard astronomers building or upgrading compact Newtonian telescopes, hobbyists assembling custom optical benches, and enthusiasts who want a fine balance of resolution and portability. It's suitable for planetary and lunar observing, targeted deep-sky work with appropriate eyepieces or focal reducers, and for imagers who need a reliable, high-reflectance primary surface in the 400–950 nm range. If you need a 114 mm optical element with a long focal length and high surface accuracy, this mirror provides a precise, serviceable solution.