Vision systems are continuously expanding the sensing capabilities of modern vibration testing, while approaching the NVH measurements from quite different technological perspectives and physics. There is a strong need in many design procedures of reliability, precision and physical soundness in the obtainable data from the experiment-based quantities of optical full field instruments. This paper wants to underline the background of the solutions, developed to obtain quantitative and physically sound precise comparisons, to help the researchers in the field expand the investigations also towards other optical full field instruments and related processing techniques. Together with the details on the test procedures, dataset transforms and structural dynamics hints, quality assessment features will be also proposed and commented with examples, as metrics of the reliability in the collected experiment-based data, for the benefit of the experts in optical instrument manufacturing, in experiment NVH & modal analysis.