Abstract: A sighting device is used to aim along a line of sight at a target. The sighting device includes a reticle structure formed of a roof prism assembly having an inclined final roof-prism mirror surface that is not perpendicular to the line of sight. The inclined final roof-prism mirror surface is the last surface of the roof prism assembly from which an optical path of the target reflects before leaving the roof prism assembly. There are two sets of sighting reference features, wherein the sets of sighting reference features are disposed on the inclined roof-prism mirror surface. A separately operable illumination source is provided for each of the sets of sighting reference features, wherein each illumination source illuminates only one set of sighting reference features.

Abstract: A cylindrical article is positioned relative to a support surface by supporting the cylindrical article from a first pair of ball bearings contacting the cylindrical article adjacent to its first end, and a second pair of ball bearings contacting the cylindrical surface adjacent to its second end. At least one of the ball bearings is moved relative to the cylindrical article to reposition the cylindrical article. The repositioning may be performed under feedback control of actuators that move the ball bearings. The article may be fixed relative to the support surface after it is properly positioned.