Abstract: Disclosed is a miniature optical system. The miniature optical system includes a first lens; a second lens; a third lens; and a fourth lens, wherein the first to fourth lenses are sequentially aligned from an object side to an image side of the system. The lenses satisfy the following equation: ?1.5<f2/ttl<?0.5, where f2 is the focal length of the second lens and ttl is a distance from an object side of the first lens to an image side of the system.

Abstract: Disclosed is a miniature optical system. The miniature optical system includes a first lens; a second lens; a third lens; and a fourth lens, wherein the first to fourth lenses are sequentially aligned from an object side to an image side of the system. The lenses satisfy the following equation: ?1.5<f2/ttl<?0.5, where f2 is the focal length of the second lens and ttl is a distance from an object side of the first lens to an image side of the system.

Abstract: A compact zoom lens system is described which includes, when viewed from an object, a first lens group with a positive refractive power; a second lens group with a negative refractive power; wherein the magnification change of the lens system can be changed by moving the first lens group and the second lens group along the optical axis of the lens system towards the object, wherein 0.45<L.sub.w /f.sub.t <0.55, 2.5<f.sub.t /f.sub.w (.phi.m)<3.0, 4.3<m2t<5. L.sub.w is the distance between the front surface which is the surface facing the object of the first lens of the first lens group, and the image plane in the wide angle position, f.sub.t is the focal length of the lens system in the telephoto position, f.sub.w is the focal length of the lens system in the wide angle position, .phi.m is the zoom ratio, and m2t is the magnification of the second lens group in the telephoto position.