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             Specify effective focal length (the default): enter a value or expression for the Effective focal length feff (SI unit: m). The default is 100 mm. 
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             Specify optical power: enter a value or expression for the Optical power K (SI unit: 1/m). The default is 0.1 m-1. 
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             If Thin lens is selected, enter the following: 
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             Radius of curvature, surface 1 R1 (SI unit: m). The default is 100 mm. This value should be positive for a convex surface or negative for a concave surface. 
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             Radius of curvature, surface 2 R2 (SI unit: m). The default is 100 mm. This value should be negative for a convex surface or positive for a concave surface. 
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             Refractive index n (dimensionless). The default is 1.5. 
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             If Thick lens is selected, enter the same parameters as for Thin lens, plus the additional Center thickness Tc (SI unit: m). The default is 0. 
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             Centroid of selection will compute the geometric center of all selected boundaries. 
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             From coordinates will give a point on the ideal lens that is a projection of a user defined point onto a plane containing the ideal lens surface. 
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             Selected point will use the point indicated in the Reference Point Selection section. 
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