Abstract: In the compact zoom lens disclosed, a first lens group of positive power includes a negative lens and two positive lenses movable for focusing, a second lens group has a negative refractive power, a positive third lens group has a positive lens and a negative lens, with the image magnification variation being effected by the second and third lens groups, a positive fourth lens group constitutes an image forming section. The relations72<.nu..sub.23 <95.11.times.10.sup.-3 <(.theta..sub.1 -.theta..sub.23)/(.nu..sub.23 -.nu..sub.1)<2.times.10.sup.-30.9.times.10.sup.-3 <(.theta..sub.9 -.theta..sub.8)/(.nu..sub.8 -.nu..sub.9)<2.3.times.10.sup.-3are satisfied for correcting chromatic aberration in the telephoto position. Here, .nu..sub.23 is the average value of the Abbe numbers of the two positive lenses in the first lens group .nu..sub.1 of the negative lens in the first lens groups, .theta..sub.

Abstract: The disclosed two-group wide-image-angle zoom lens is zoomed by changing the distance between the front and the rear group. The front group exhibits a negative refracting power and includes a first positive lens, a second negative lens concave toward the image end, a third positive lens, a fourth negative lens concave toward the image end, and a fifth positive image lens convex toward the object end, all in sequence; the rear group is closer to the image end than the front group, exhibits a positive refracting power, and includes a first positive sub-group, a second positive sub-group, a third negative sub-group, and a fourth positive sub-group.

Abstract: The present invention relates to a lens realizing a soft-focus effect by changing the air space between the front lens group with a positive power and the rear lens group with a negative power, thus increasing selectively the spherical aberration among the Seidel aberrations and maintaining the other aberrations constant. The front lens group consists of a positive meniscus lens with a convex surface at the front side and a positive meniscus lens consisting of a bi-convex lens and a bi-concave lens, being cemented on each other in sequence, while the rear lens group consists of an aperture, a bi-concave lens and a positive lens consisting of a negative and a positive lens being cemented on each other in sequence.