Abstract: An optical system includes an optical assembly frame having an input portion, an output portion, and an objective lens assembly disposed at the input portion of the optical assembly frame. The objective lens assembly has an objective lens central optical axis. An eyepiece lens assembly is disposed at the output portion of the frame. The eyepiece lens assembly has an eyepiece lens central optical axis parallel to the objective lens central optical axis and offset from the objective lens central optical axis by a distance. An inverting image intensifier is disposed between the objective lens assembly and the eyepiece lens assembly. The image intensifier has an image intensifier optical axis parallel to the objective lens central optical axis and parallel to the eyepiece lens central optical axis. The image intensifier optical axis is offset from both the objective lens central optical axis and the eyepiece lens central optical axis by about half the distance.

Abstract: An optical system includes an optical assembly frame having an input portion, an output portion, and an objective lens assembly disposed at the input portion of the optical assembly frame. The objective lens assembly has an objective lens central optical axis. An eyepiece lens assembly is disposed at the output portion of the frame. The eyepiece lens assembly has an eyepiece lens central optical axis parallel to the objective lens central optical axis and offset from the objective lens central optical axis by a distance. An inverting image intensifier is disposed between the objective lens assembly and the eyepiece lens assembly. The image intensifier has an image intensifier optical axis parallel to the objective lens central optical axis and parallel to the eyepiece lens central optical axis. The image intensifier optical axis is offset from both the objective lens central optical axis and the eyepiece lens central optical axis by about half the distance.

Abstract: An optical system includes a lens cell having a generally cylindrical lens cell body. The lens cell body has a lens cell central longitudinal axis and a lens cell optical axis eccentrically offset from the lens cell central longitudinal axis. A sleeve includes a generally cylindrical sleeve body having an outer surface with a first longitudinal axis and an inner surface with a second longitudinal axis eccentrically offset from the first longitudinal axis. The lens cell is inserted into the sleeve. A housing has a generally cylindrical body with the sleeve at least partially inserted into the housing. A clip is disposed about at least a portion of the circumference of the housing. The lens cell and the sleeve are rotated relative to each other and to the housing such that the lens cell optical axis is aligned in a desired location.

Abstract: An optical system includes a lens cell having a generally cylindrical lens cell body. The lens cell body has a lens cell central longitudinal axis and a lens cell optical axis eccentrically offset from the lens cell central longitudinal axis. A sleeve includes a generally cylindrical sleeve body having an outer surface with a first longitudinal axis and an inner surface with a second longitudinal axis eccentrically offset from the first longitudinal axis. The lens cell is inserted into the sleeve. A housing has a generally cylindrical body with the sleeve at least partially inserted into the housing. A clip is disposed about at least a portion of the circumference of the housing. The lens cell and the sleeve are rotated relative to each other and to the housing such that the lens cell optical axis is aligned in a desired location.