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Data Source Request for Surface Absorption or Reflectance To Visible Light

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Hi,

I am a mechanical design engineer, in charge of design and development of variant electro-optical stsyems. I have met some stray light and veiling glare issues caused by reflectance of light ray from mechanical surfaces at a few optical systems. We had carried out a large number of experiments to find out root cause of veiling glare for a certain product, it did work. However, it is very difficult to solve this veiling glare issue for all products since the causes from design parameters and optical requirements are different for different systems. Hence I plan to model the veiling issue by using the mathematical methods and work with optical design engineer to solve this issue.

The first step is to calculate the reflectance of visible light through different entrance angle from metal part surface. The surface finishes are normally: Black Anodize Per Mil-A-8625 [link is to spec at TechStreet], Type II, Class 2 & SandBlasting using AL2O3 with different grit size (320, 150, 60, etc.), we also applies hard anodize for optical assembly used at medical systems. But now our problem is that we are not able to find out data of absorption or reflectance of the sandblasted & Black surfaces to visible light.

Does any body have any tips on the data sources or any advice on the veiling glare issue I talked above?

Thanks and best regards,

Bilong Lin
Mechanical Design Engineer - Singapore