A lens system and a portable device employing the lens system are provided. The lens system includes at least three lenses and an infrared cut filter disposed between any of the lenses to prevent redness from occurring at a center region of an image as the lens system is miniaturized. An angle .crclbar..sub.1 at which light is incident on the infrared cut filter satisfies 14.degree..ltoreq..theta..sub.1.ltoreq.16.degree..