Astro-Tech Dielectric Quartz Mirror Diagonal
Best high performance upgrade for amateur astronomers seeking thermal stability.
This premium diagonal upgrades standard setups with a low-thermal-expansion quartz mirror for superior stability. Its high-reflectivity dielectric coatings ensure maximum light transmission, delivering sharper, higher-contrast views for critical planetary and lunar observation.
$119.95
Who it's for
- Astronomers observing in environments with rapidly changing outdoor temperatures
- Deep-sky observers seeking maximum brightness and contrast for faint nebulae
- Owners of high-end eyepieces who prioritize gear protection and longevity
Who should skip it
- Users with lightweight portable setups or entry-level mounts
- Budget-conscious hobbyists looking for basic functional upgrades
- Minimalist travelers using small-aperture telescopes with limited clearance
Performance breakdown
Optical Reflectivity
Dielectric coatings deliver industry-leading light transmission for exceptionally bright, crisp views.
Thermal Stability
Quartz substrate resists expansion, keeping your focus locked during long sessions.
Build Quality
Precision-machined aluminum housing offers a robust, premium feel in the hand.
Eyepiece Security
Brass compression ring holds expensive eyepieces firmly without marring their barrels.
Contrast Performance
Matte black interior finish effectively suppresses stray light for deeper blacks.
Compatibility
Standard 1.25-inch sizing fits most refractors and catadioptric telescopes seamlessly.
Key Specs
Barrel Size
1.25 inches
Mirror Material
Quartz
Reflectivity
99%
Coatings
46-layer dielectric
Housing Material
Machined aluminum
Filter Thread
1.25 inches
Eyepiece Clamp
Brass compression ring
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