Abstract. Optical metrology includes a set of non-contact measurement methods to quantify shapes, surfaces, distances, deformations, displacements or colorimetry. Optical measurement methods have the advantage of being non-intrusive while allowing instantaneous measurements over extended areas. The applications of optical metrology concern all fields of engineering. The paper presents developments related to surface and to 4D measurements (3D displacements + time). Different methods in the fields of solid and fluid mechanics are described and are illustrated by applications. Their applications in different fields for static or dynamic measurements and the limits is discussed in the paper.