Several common impediments to successful lens design can be removed by application of new techniques. These R"{P#U,HNO
involve using information that has long been calculated during the design process, but then discarded. Problems so ;D <;pW
addressed include the nuisance of discovering ray failures in the starting configuration, and that of tolerance zCS& w
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desensitization, am Optical design codes today have capabilities that were not imagined at the outset, roughly 40 years ago, when we were first trying to figure out how to make them work. Since then, although algorithms have matured and a vast amount of information is calculated, designers still face some practical difficulties. These can be remedied with clever use of information that is already available but usually discarded. Several areas respond well to the new tools that this idea leads to. The first is the common situation when rays will not trace through the intended starting configuration, causing the designer to waste time just trying to get started. Others involve use of 3rd and 5th-order aberrations in a new way.ong others.
