Despite the widespread use of night vision imaging systems in today’s military, the problem of directly measuring the spatial frequency response of these systems has been ignored. Modulation Transfer Function (MTF) performance specifications have been extensively researched for the components of night vision imaging systems such as the lenses and the image intensifier tube. The current method for calculating the system MTF is to combine the MTFs of all the components of the imaging system. Little research has been performed to directly measure the MTF of the entire system. This thesis describes a method to directly measure the modulation transfer function for an AN/AVS-6 Aviator’s Night Vision Imaging System (ANVIS). This method is based on the traditional slit technique and uses a Photo Research PR-900 video photometer as the detector. Comparisons between the direct measurement and the component combination calculation demonstrate the accuracy of the direct measurement. / Master of Science