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.

The zoom lens includes a positive first lens group, a negative second lens group, a positive third lens group, a negative fourth lens group, a negative fifth lens group, and a positive sixth lens group in order from an object side. All distances between adjacent lens groups change during zooming. The first lens group consists of a negative lens, a positive lens, and a positive lens in order from the object side. Only the fourth lens group moves to an image side during focusing from a long range to a short range. Conditional Expression is related to lateral magnification of the fourth lens group and a lateral magnification of the sixth lens group is satisfied.

The disclosure relates to a magnification adjusting assembly. In one embodiment, the magnification adjusting assembly comprises a ring having an inner surface and an outer surface. In one embodiment, a groove is disposed around the inner surface of the ring. In one embodiment, at least three ball bearing structures are secured in the groove by a compressible material.

The disclosure relates to a magnification adjusting assembly. In one embodiment, the magnification adjusting assembly comprises a ring having an inner surface and an outer surface. In one embodiment, a groove is disposed around the inner surface of the ring. In one embodiment, at least three ball bearing structures are secured in the groove by a compressible material.

An optical system includes an optical element having negative refractive power and disposed on at least one of an object side and an image side of an intersection of an optical axis and a pupil paraxial ray. The optical element is made of a glass material and satisfies a predetermined condition.

An optical system includes an optical element having negative refractive power and disposed on at least one of an object side and an image side of an intersection of an optical axis and a pupil paraxial ray. The optical element is made of a glass material and satisfies a predetermined condition.

A high etendue modular finite conjugate lens assembly has a zooming component with multiple lens groups, including four lens groups that each feature a doublet, and a lens attachment lens assembly comprising a fifth doublet, wherein the lens assembly is configured to exhibit between 0.45 and 4.65 mm.sup.2sr of etendue, and a ratio of highest to lowest magnification between 5.5:1 and 16:1, and a magnification of at least 2× at one or more points of a zoom range.

A high etendue modular finite conjugate lens assembly has a zooming component with multiple lens groups, including four lens groups that each feature a doublet, and a lens attachment lens assembly comprising a fifth doublet, wherein the lens assembly is configured to exhibit between 0.45 and 4.65 mm.sup.2sr of etendue, and a ratio of highest to lowest magnification between 5.5:1 and 16:1, and a magnification of at least 2× at one or more points of a zoom range.

A finite conjugate optical assembly, comprising a lens with a core zoom module that includes five optical groups that are configured to exhibit at least 1.58 mm.sup.2sr of etendue at a lowest magnification position, and a ratio of highest to lowest magnification of at least 7:1, and to provide a maximum magnification of 2× or greater.

A finite conjugate optical assembly, comprising a lens with a core zoom module that includes five optical groups that are configured to exhibit at least 1.58 mm.sup.2sr of etendue at a lowest magnification position, and a ratio of highest to lowest magnification of at least 7:1, and to provide a maximum magnification of 2× or greater.