Abstract: A variable magnification optical assembly having a housing with a fixed location for its object and image windows, and a carriage which is linearly moveable within the housing and which has mounted thereon at least one mirror. The carriage mirror(s) cooperates with at least one mirror affixed on the housing to define a first and a second light path within the optical assembly; with the respective paths being dependent upon the position of the carriage within the housing. The various mirrors are positioned within the optical assembly such that the light paths have different conjugate ratios. Therefore, a change in the magnification obtained within the assembly is accomplished with only a linear displacement of the carriage.