Product Description
Vintage Edmund Scientific 150mm λ/2 Precision Optical Flat Mirror
This is a classic λ/2 precision reference flat from Edmund Scientific, the trusted supplier for generations of amateur telescope makers (ATMs) and optical workshops. With a substantial 150mm diameter and 25mm thickness, it offers the stability and accuracy required for serious optical testing and alignment.
Key Specifications:
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Diameter: 150 mm (~6 inches)
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Thickness: 25 mm (minimizes distortion, ensures thermal stability)
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Flatness: λ/2 wavefront (suitable for reliable reference testing)
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Material: Likely fused silica or Pyrex low-expansion glass
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Coating: Protected aluminum first-surface (high broadband reflectivity)
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Condition: Excellent clean surplus – reflective surface is bright and intact
Why This Edmund Flat Is a Benchmark Tool:
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Proven Legacy: Edmund optical flats were the standard for ATM mirror testing and lab alignment for decades.
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Rigid Design: The 25mm thickness ensures the flat maintains its figure during use, critical for repeatable measurements.
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Ready for Serious Work: Delivers reliable, accurate results for testing optics up to moderate f/ratios.
Applications:
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Telescope Mirror Testing: Reference flat for Foucault, Ronchi, or interferometric testing of parabolic and spherical mirrors.
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Optical Alignment & Autocollimation: Essential tool for aligning optical benches, lasers, or imaging systems.
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Surface Verification: Checking the flatness of other optical surfaces in workshops or labs.
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Historical & Educational: A functional piece of optical history, perfect for teaching wavefront optics, metrology, or the ATM tradition.



