The aim of this work was to provide a comprehensive insight concerning coated films to be used for ITER first mirrors. The influence of the mirror crystallite size has been addressed as well as the coating techniques to provide nanocrystalline films. Review of coated mirror tests in laboratories or in tokamaks has been presented. A wide angle camera system has been installed in JET-ILW which is composed of a mirror box with 3 stainless steel mirrors coated with Rh viewing the torus through a conically shaped aperture. The system delivered the required image quality for plasma monitoring and wall protection, a new system was already installed in JET.