Optical filters allow passage only of light with specific characteristics (for example, light of a specific wavelength), blocking (filtering) all other light. Optical filters are widely used in photography, optical devices, and lighting. When attached to a lens of a camera, telescope, microscope, or other device, lens filters filter the light supplied to the device. Most lens filters are optical filters that filter light based on wavelength or polarization, but some create a soft effect or ray systems; all are referred to as "lens filters. "