This paper presents a method of high-speed production lens testing by modulation transfer function (MTF) measurement. An MTF measuring system is developed for the purpose of routine go-not go testing of photographic lenses. An operator can test one lens in less than ten seconds which includes not only the time of MTF measurement but also the time of operator's manual work for attaching and detaching a lens to/from the system. The photodiode arrays are utilized as scanners of line spread functions. MTFs are measured for on-axis and off-axis position in the image field of 24x35mm film format. There are 14 items which are checked by MTF values, and if all the measured MTF values for each of the items clear the specified values, ao-sign is displayed on the indicator. The system can be used for testing photographic lenses that are in the range of focal length from 35mm to 300mm, and F-stop from 1.2 to 5.6.