In this study, it is intended to determine how a core material behaves under the influence of a static magnetic field (MF), which causes magnetic losses in electrical machines. In addition, it is aimed to design an optical system, which can determine the performance of the core materials under MF effect. First, when standard core materials are exposed to a MF, these materials make rotational movements. The amount of rotation is then calculated and the work amount done after this rotation is tracked. Consequently, from the work quantities, it can be decided whether the materials are good core materials or not. This shows that the optical system can make a non-contact performance analysis for the materials in certain thicknesses, which may be the core material. Thus, this system can be used to determine whether the newly manufactured core material is a good one according to the work quantities obtained for standard equivalents. At the same time, this is the first study about performance analysis of core materials achieved by optical methods.