In this paper, the optical images of glow discharge plasma and the finite element method simulation of the magnetic field strength in a balanced and two types of unbalanced DC circular planar magnetron sputtering sources are presented. The investigation showed that wherever the magnetic field strength is stronger, the intensity of light and the ionization are greater and consequently, the deposition is higher. The comparison of recorded optical images with the finite element simulation results of the magnetic field strength indicated the correlation between regions of high magnetic field strength and high light emission. Manuscript profile