The concept of the assessment of image quality by means of the optical transfer function (OTF) has progressed in its development through the stages of hardware development and acceptable correlation between measured and computed data. As a result of this work OTF is accepted as a viable means of specifying and measuring image quality in the standards and research field for which sophisticated instrumentation has been designed. Present development is aimed at producing instrumentation with OTF used as one parameter in complex equipments capable of measuring a number of optical parameters, evaluating and presenting the overall value of image performance.