Method of determining Gaussian parameters for zoom systems with multiple moving lens groups

A new computable method of determining Gaussian parameters of zoom systems with multiple moving lens groups is presented. In the method, the lens groups are no longer divided as zoom group(s) and compensating group(s). Displacements and focal lengths of all the moving lens groups are taken as variables in optimization, and the Gaussian parameters are solved for all the zoom positions simultaneously, with the F-number of each lens group constrained to a rational value. A test program is developed using the algorithm. The results of a design example show that the method is practical and it is a step toward intelligent computer-aided design (ICAD) of zoom systems.