AbstractWhen testing the surface quality of the finest structures, white‐light interferometers are in their element, both in production and development, as well as in laboratories and research. This measurement principle works on almost all materials, operates without contact, providing surface profiles in 3D with height resolutions in the nanometer range. Today, large‐area measurements are just as possible as detailed investigations with high lateral resolution, e.g. for surface characterization of wafers, optical components or in tribology.