Variable Focal Length High Speed Lens

This report describes the development and prototype manufacture of a high speed f2.4 zoom lens to work in the near infra-red 0.7 to 0.9mm in conjunction with an image tube night viewing system. The development or design effort covered a period of 32 months and proved to be a very difficult design problem which required the performance objectives specs to be modified somewhat in order to permit the realization of a successful design. The completed design was fabricated in 17 months as a bench model prototype and found to meet the expected performance values. This unit was delivered for final testing in December 1971.