The book covers the theories and physics of advanced new optical measuring methods and problems of experimental performance, recent achievements in the basic interferometric methods holography, speckle-interferometry, shearography as well as linear/non-linear photoelasticity and photoviscoelasticity, Moire- and grid-techniques. It deals with theory and application of digital image processing, methods of data recording, data processing and visualisation, with mathematical/numerical procedures for final evaluation of digitised measured data and the principle of hybrid techniques. It provides an introduction to the new perceptions of methods in experimental solid mechanics, should encourage scientists to deal intensively with the theories for further developments, and enable practitioners to at least understand the theory and physics of the new achievements and to apply the methods in research als well as in developments in practice.