A method and system for controlling an image printing system in the presence of reload defects are provided. The penetration depth thereof is equal to or larger than 150 nm in a wavelength range in the far ultraviolet range wherein the penetration depth depends on a wavelength of the far ultraviolet light, refractive index of an object to be measured, refractive index of optical material of the probe and incident angle of the far ultraviolet light at an interface between the probe and the object. The core consists of one or more layers of which at least one is reinforced with long fibers.