A finite conjugate optical assembly including a core zoom module that includes five optical groups that are configured to provide a ratio of highest to lowest magnification between 5.5:1 and 16:1. A lens attachment module and rear adapter module may be disposed, respectively, on an object side and an image side of the optical assembly. The optical assembly may exhibit an approximate etendue between 0.95 and 4.65 mm.sup.2sr, and may have a magnification of 2 or more at one or more points of the zoom. The optical assembly may be configured in accordance with between 6.6 MP and 32 MP image sensors.

A finite conjugate lens assembly including an afocal zooming component that has five optical groups that are configured to provide a ratio of highest to lowest magnification between 5.5:1 and 16:1. A lens attachment module and rear adapter module may be disposed, respectively, on an object side and an image side of the optical assembly. The lens assembly may exhibit an approximate etendue between 0.95 and 4.65 mm.sup.2sr, and may be configured in accordance with between 6.6MP and 32MP image sensors.

A zoom lens including in order from an object side: a positive first unit configured not to move for zooming; a negative second unit configured to move to the image side for zooming to a telephoto end; and a relay lens unit configured not to move for zooming, wherein the first unit consists of five lenses including, in order from the object side, a negative lens, a positive lens, a positive lens, a positive lens and a positive lens, or six lenses including, in order from the object side, a positive lens, a negative lens, a positive lens, a positive lens, a positive lens and a positive lens, and a refractive index of the negative lens in the first unit, an Abbe number of the negative lens, a focal length of the negative lens, and a focal length of the first lens unit are appropriately set.

A zoom lens includes, in order from the object side, a first lens unit having a positive refractive power that does not move for zooming, second to fourth lens units each having a negative refractive power that moves for zooming, and a relay lens unit having a positive refractive power and being closest to the image side that does not move for zooming. The second lens unit moves to the image side from the wide-angle end to the telephoto end. When a focal length fx determined by a focal length fw of the zoom lens at the wide-angle end and a zoom ratio Z is fx=fwZ.sup.0.38, the zoom lens satisfies 0.05<L2min/L2w<0.98, where L2min is a minimum distance between the second and third lens units in a zoom range from the wide-angle end to the focal length fx, and L2w is a distance between them at the wide-angle end.

A zoom lens includes, in order from object-side, a fixed positive first group including three-or-more lenses, a negative second group including a unit moving toward image-side during zooming toward telephoto-end, a positive third group including a unit moving toward object-side during zooming from wide-end to telephoto-end, a negative fourth group moving during zooming and focusing, and a rear group. Focal lengths of the first group and the zoom lens at wide-end, a movement amount of a unit moving by largest amount during zooming toward telephoto-end in the second group, a largest value of position change between wide-end and telephoto-end of units moving toward an object side during zooming from wide-end to telephoto-end, refractive index for d-line of a positive lens closest to image-side in the first group, and average refractive index for d-line of positive lenses of the first group other than the positive lens are appropriately set.

Provided is a zoom lens, including, in order from an object side to an image side: a positive first lens unit that does not move for zooming; a negative second lens unit that moves during zooming; and a positive N-th lens unit that does not move for zooming and is arranged closest to the image side. Among lenses constructing the second lens unit, two lenses closest to the image side are a positive lens and a negative lens, and partial dispersion ratios for g-line and F-line and Abbe numbers for a d-line of the positive and negative lenses, and an average value of refractive indices of all the lenses of the second lens unit are appropriately set.

A zoom lens consists of, in order from the object side, a positive first lens group, a negative second lens group, a negative third lens group, a negative fourth lens group, a positive fifth lens group, and a positive sixth lens group. The first lens group and the sixth lens group are fixed with respect to an image plane, and a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group changes, and a distance between the third lens group and the fourth lens group changes, and a distance between the fourth lens group and the fifth lens group changes, and a distance between the fifth lens group and the sixth lens group changes during magnification change from a wide angle end to a telephoto end.

A rear adapter module for a finite conjugate optical assembly and camera is configured to couple with a core zoom module. A lens assembly of the rear adapter module includes three or more lens elements and has a positive focal length. The lens assembly exhibits a pupil size of between 16 and 25 mm and a pupil depth greater than 50 mm.

A finite conjugate lens assembly with modular interchangeable components includes a zooming component that includes three independently movable lens groups that are disposed within the lens assembly between a pair of static lens groups. The lens assembly exhibits an etendue of between 0.95 and 4.65 mm.sup.2sr.

Zoom lenses and image pickup apparatuses are provided herein. One or more zoom lenses may include a plurality of lens units, which include, in order from an object side to an image side, a first lens unit with positive refractive power that does not move for zooming, an intermediate group including at least three movable lens units that move for zooming, and a rear lens unit with positive refractive power that does not move for zooming. Each distance between adjacent lens units changes during zooming. The first lens unit includes a focus sub-lens unit that moves for focusing. One of the at least three movable lens units in the intermediate group includes an aperture stop. A predetermined inequality is satisfied.