Optical System Mtf Fast Measuring Instrument

Optical Transfer Function/Modulation Transfer Function is recognizes as one of most effective and objective methods to evaluate optical imaging systems. With the manufacture level of optical instruments improving and range of usage spreading, an accurate and efficient MTF measurement instrument with large testing range is in great demand. Based on MTF measurement theory, it is necessary to adopt increasingly developed computer technology, advanced image grabbing components and efficient image processing methods to make MTF measurement instruments more accurate, quick-testing, having larger testing range and smaller size.Methods to evaluate imaging systems, theories and general methods of MTF measurement are studied in detail in this paper. After analyzing the strength and weakness of current MTF-testing instruments, a method to quickly measure the MTF of optical systems is proposed. By using white-black stripes on LCD (Liquid Crystal Display) as object, CCD as component of image grabbing and computer to do image processing work, it can get the contrast of images under different spatial frequencies. Therefore MTF curves of optical systems are produced. As an example to this measurement method, an equipment testing of the lens of cameras is installed together with application software. The result of this testing equipment is displayed and the function, precision and places needed to improve are also discussed.