A method for modifying the spectrum of light rays passing through an objective lens to an electronic camera that includes providing an interference type filter within the objective lens. The interference type filter may be a coating on a separate optical element added to the objective lens or on a normal optical component of the objective lens. The interference filter coating is located along the optical axis where the light rays are substantially collimated and have a minimum light ray incidence angle with respect to the coating surface, which angle should not exceed 15 degrees for any of the light rays passing therethrough.