Material

The material used for each surface is usually specified by entering the name of the glass in the "Material" column on the Lens Data Editor. The glass name entered must be in one of the currently loaded glass catalogs. The default catalog is the "Schott" catalog; others are available.

To use multiple glass catalogs, or to review, edit, or append the glass catalogs, see the section called Using Material Catalogs. To specify that a particular surface be a mirror, use the glass name "mirror".

If a surface or object has the material type MIRROR, and no coating is specified, then the surface is assumed to be coated with a thick layer of aluminum, with an index of refraction 0.7 - 7.0i. The aluminum layer is assumed to be thick enough that no light propagates past the layer. This means that an uncoated mirror surface has a reflectivity of less than 1, though the exact value will depend on the polarization of the rays.

There is an optional "/P" command that may be appended to the glass name when entering a new glass. This option will cause OpticStudio to alter the curvatures before and/or after the surface to attempt to maintain a constant power for the lens element. For example, if the glass type is already BK7, entering a new glass type of "SF1/P" will change the glass type to SF1 while adjusting the radii of the surface and the surface after, to maintain constant power. OpticStudio considers the front and back vertex powers, as well as the element power correction due to the lens thickness. The algorithm adjusts both front and back curvatures if the lens is in air. If either the front or back surfaces are adjacent to another glass element, then only the curvature adjacent to the air is adjusted.

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• Clear Semi-Diameter or Semi-Diameter