(under subclass 642) Subject matter wherein the lens produces an image having soft or indistinct outlines.
(1) Note. The lens diffusion characteristics may be effected by any one of the following: (a) frosting the lens surface, (b) shifting the lens components relative to each other, (c) placing aspheric surfaces adjacent or on one or more components of the lens, (d) adding a transparent plate or additional lens component to the lens, (e) undercorrecting the lens, (f) introducing aberration to the lens, etc.
