Edmund Optics 75mm concave mirror

This is a research/ lab grade precision 75 mm concave spherical first-surface protected Aluminized
Mirror – f/3.3 from Edmund Optics (R=0.5m/fl 250 mm). It is a surplus made for demanding lab or
industrial use, not consumer-grade.
The protected aluminum coating offers broad reflectivity (~85–95%) across visible to near-IR, with
peak ~90% in visible)
Condition: Appears excellent — clean surface, minor edge nick but not affecting the optical area
Key Specifications
• Diameter: 75 mm (≈3 inches)
• Focal Length: 0.25 m (250 mm)
• Radius of Curvature: 0.5 m (500 mm)
• Thickness: 10 mm (balanced for rigidity without excess weight)
• Type: Concave spherical, first-surface aluminized (protected aluminum coating)
• Material: Fused silica substrate
Applications and Uses: This fast f/3.3 concave mirror excels at focusing light and forming images,
making it versatile for:
• Magnifying mirror for makeup, shaving, or detailed inspection — produces clear, enlarged
upright images at close range—perfect for detailed personal grooming.
• Solar concentrator for science demos — focus sunlight to a hot spot capable of igniting paper
or heating small objects (use extreme caution, protective eyewear, and never look directly at the
focal point).
• Projection Systems: In simple overhead projectors, slide projectors, or homemade movie
setups—place an object/image near the focal point to project an enlarged real image onto a
screen/wall.
• Educational experiments — ideal for ray optics demos, illustrating real/virtual image
formation, focal points, and spherical aberration, and mirror laws.
• Laser focusing or alignment with low-power visible lasers (e.g., HeNe or pointers) for beam
concentration and experiments.
• DIY beam expander or reflective microscope objective when paired with lenses for custom
optics projects.
• Fun optical illusions like the “floating coin” trick (object appears suspended in mid-air