Determining optimal first-order focal lengths of zoom lenses through Monte Carlo simulations

摘要

Choosing first-order group focal lengths for complex zoom lenses is a problem with too many variables to have a simpleanalytical solution. Furthermore, the group power balance has a large impact on performance, but there isn’t a well-knownway to quickly determine the potential design performance of a given power grouping. This often leads to the choice ofpoor starting points increasing both the difficulty of the design process and the time to find a solution. To solve thisproblem (e.g. for a four-group zoom lens) a Monte Carlo like program has been written that first randomly chooses groupfocal lengths, finds first-order solutions, and checks for zoom group collisions. Then if a solution is valid it creates a lensdesign which is quickly optimized and evaluated for performance with real ray tracing using CODE V. The program keepstrack of all solutions and is then able to automatically sort and identify power groupings with strong performance,simplifying the overall design process. Data collected by the program can also be used to sort solutions for minimumdiameter, minimum length, and other design parameters.