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.

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.

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 6.6 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 6.6 MP and 32 MP image sensors.

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 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 zoom lens including a front group and a rear group, wherein a lens group arranged on an object side of a widest air interval at a wide-angle end is defined as the front group and a lens group arranged on an image side of the widest air interval at the wide-angle end is defined as the rear group, the front group having a negative refractive power, the rear group having a positive refractive power. Changing focal length from the wide-angle end to the telephoto end is performed by changing an air interval between the lens groups.

An extender lens unit to be inserted into and removed from an optical path in a relay lens unit included in a zoom lens consists of a front unit having a positive refractive power, a middle unit having a negative refractive power, and a rear unit having a negative refractive power. The extender lens unit includes three negative lenses. The middle unit includes a negative lens. An average refractive index of positive lenses included in the extender lens unit, an average refractive index of negative lenses included in the extender lens unit, a focal length of the negative lens included in the middle unit, and a focal length of the middle unit are appropriately set.

A finite conjugate optical assembly including a core zoom module that includfes 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 optical assembly including a core zoom module that includfes 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.