Abstract: A compact zoom lens system comprises a front negative lens component and a rear positive lens component with a variable air space between the front and the rear lens components. The front negative lens component consists of two lens elements and the rear lens component consists of two or three lens elements. A plurality of aspherical surfaces are employed for the compact zoom lens system. Furthermore, some zoom lens system includes an additional negative lens component having a weak refractive power behind the rear lens component.

Abstract: A compact zoom lens system comprises a front negative lens component and a rear positive lens component with a variable air space between the front and the rear lens components. The front negative lens component consists of two lens elements and the rear lens component consists of two or three lens elements. A plurality of aspherical surfaces are employed for the compact zoom lens system. Furthermore, some zoom lens system includes an additional negative lens component having a weak refractive power behind the rear lens component.

Abstract: A compact size zoom lens system ranging to a wide field angle and having a high zoom ratio of up to 10. The zone lens system is composed of, from the object to the image side, a positive first lens group, a negative second lens group, a positive third lens group and a negative fourth lens group, and fulfills the following conditions:0.15<f.sub.s /f.sub.1 <0.30.45<f.sub.L /f.sub.s .multidot..vertline.f.sub.2 .vertline.)<0.80.15<f.sub.3 /f.sub.1 <0.32where f.sub.1, f.sub.2, and f.sub.3 are the focal lengths of the first, second and third lens groups respectively, and f.sub.s and f.sub.L are respectively the shortest and the longest focal lengths of the zoom lens system. When the zoom lens is zoomed from wide to tele, the first lens group moves toward the object side, the distance between the second and third lens groups is decreased, and both the second and third lens groups are moved toward the object side. The following conditions may be added:0.35<f.sub.1 /f.sub.L <0.41.2<.

Abstract: In a triplet type objective for a compact lens shutter camera with a diaphragm arranged behind the lens system, the first and the second lens elements are formed of plastic and the third lens element is formed of glass, so that it is advantageous in manufacturing cost and weight. Therefore, an F No. of the objective is small and aberrations, for example astigmatic difference, are corrected well.