Using small glass catalogs

Changes in glass catalogs from the major manufacturers, Schott, Ohara, Hoya , Coming, and Summita, are a future certainty. The ongoing efforts of these companies to eliminate arsenic. lead, and other environmentally unfriendly materials may well have an additional effect on the size of their catalogs also. We should not assume a zero-sum game, however. Environmental concern s may not lead to permanently smaller catalogs, though many have speculated that in the near term this might be so. However, from the designer's persp ective, very smalt, abbreviated class catalogs, constructed for special pur poses, can speed the glass selection process. Several examples will be disc ussed, based on derivative libraries suggested by Zhang, Shannon, and Walke r. Streamlined libraries tailored for special purposes can be used effectiv ely in the latest lens design software. Future software tools may speed thi s selection process by the use of algorithms that treat the problem as a "b lack box," using logic tools derived from probability studies of the patent literature. (C) 2000 Society of Photo-Optical Instrumentation Engineers [S 0091-3286(00)01407-0].