Abstract: An interface facility has a first facility element connected to an ocular, a device case configured to connect to a smart device, a second facility element connected to the device case, the first and second facility elements being configured to connect to each other in a connected condition and to detach from each other, the first facility element being registered with a first optical axis associated with the ocular, the second facility element being registered with a second optical axis associated with the camera, the first and second optical axes being registered with each other when the first and second facility elements are in the connected condition, such that the camera records images generated by the ocular. The first and second facility elements may comprise a bayonet mount.

Abstract: An interface facility has a first facility element connected to an ocular, a device case configured to connect to a smart device, a second facility element connected to the device case, the first and second facility elements being configured to connect to each other in a connected condition and to detach from each other, the first facility element being registered with a first optical axis associated with the ocular, the second facility element being registered with a second optical axis associated with the camera, the first and second optical axes being registered with each other when the first and second facility elements are in the connected condition, such that the camera records images generated by the ocular. The first and second facility elements may comprise a bayonet mount.

Abstract: A diopter adjustment device for an optical device such as a riflescope includes a first tubular member having overlapping left-handed and right-handed external threads, a second tubular member has internal threads mated with either the left-handed or right-handed external threads of the first tubular member, and a stop nut threaded onto the first tubular member via internal threads that are of opposite handedness as the internal threads of the second tubular member. A diopter lens is mounted in one of the first and second tubular members and movable therewith relative to the other of the first and second tubular members to adjust a diopter setting or focus of the optical device. Because the internal threads of the nut and the second tubular member have opposite handedness, the nut provides greater resistance to inward movement of the diopter lens than conventional locking diopter adjustments.