An optical system includes an aperture stop configured to direct light through the optical system, an inverting prism assembly configured to receive light from the aperture stop and direct light through the optical system, and a field stop configured to receive light from the inverting prism assembly and direct light through the optical system to an operator of the optical system. A point-of-impact is identified in object space and a point-of-aim is identified in afocal space of the optical system. The inverting prism assembly is configured to be pivoted about a center of the aperture stop to effect alignment of the point-of-impact and point-of-aim in the afocal space so that the point-of-aim is coincident with the optical axis.