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.

An optic focusing cover. The optic focusing cover includes a cylindrical body with openings at both ends. A corrective lens is disposed within the cylindrical body such that it covers the entire opening. The corrective lens is capable of further magnifying the telescope. A cap is attached to a first side of the cylindrical body, the cap is capable of going from an open to a closed configuration. A second end of the cylindrical body is configured to be accepted by a telescope.

An optic focusing cover. The optic focusing cover includes a cylindrical body with openings at both ends. A corrective lens is disposed within the cylindrical body such that it covers the entire opening. The corrective lens is capable of further magnifying the telescope. A cap is attached to a first side of the cylindrical body, the cap is capable of going from an open to a closed configuration. A second end of the cylindrical body is configured to be accepted by a telescope.

Certain aspects of a novel weapon sight system combine a direct view, a visible light video view, and an infrared (IR) video view mode. Each of the view modes may be viewed individually or simultaneously with one or more of the other view modes through a single viewing aperture. Further, the one or more view-modes may be provided while providing a bore-sighted reticle superimposed on the selected view. Further, the reticle may be powered separately from the video view electronics enabling use of the reticle regardless of the power status video view electronics.

An anti-reflective lens and method for treating a lens to reduce visible light and ultraviolet light at levels perceptible to the vision system of an animal and a detection device having tetra-chromatic vision or di-chromatic vision. The treatment method produces an optical substrate that is less perceptible to an animal and detection device perceptible to view through the UV light spectrum. The method provides a substrate treated on opposite sides with an anti-reflective coating so that reflections from visible light and UV light are not visible to the animal and detection device, from incident angles between 0° to 60°. The anti-reflective coatings are applied in varying amounts of constituents and thicknesses, consisting of: adhesion layer, low index material (SiO.sub.2), high index material (ZrO.sub.2), and superhydrophobic layers. The substrate is initially UV treated, and then coated with the anti-reflective coating to minimize visible light and UV light reflection between 300-400 nanometers.

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.

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.

Certain aspects of a novel weapon sight system combine a direct view, a visible light video view, and an infrared (IR) video view mode. Each of the view modes may be viewed individually or simultaneously with one or more of the other view modes through a single viewing aperture. Further, the one or more view-modes may be provided while providing a bore-sighted reticle superimposed on the selected view. Further, the reticle may be powered separately from the video view electronics enabling use of the reticle regardless of the power status video view electronics.

There is provided a dot sight device including a housing being configured to have an open front and an open rear, and a light path connecting a user with a target along a central axis of the light path disposed therein. A dot reticle generating unit generates a plurality of light rays for forming a dot reticle. A reflective mirror reflects the light rays provided from the dot reticle generating unit toward the user to form an image on a target side. A compensating plate is disposed along the light path of the housing together with the reflective mirror and passes through the light rays coming from the target to be directed toward the user. The compensating plate is configured to suppress or minimize one or more movements of the image of the target caused by one or more movements of the dot sight device.

There is provided a dot sight device including a housing being configured to have an open front and an open rear, and a light path connecting a user with a target along a central axis of the light path disposed therein. A dot reticle generating unit generates a plurality of light rays for forming a dot reticle. A reflective mirror reflects the light rays provided from the dot reticle generating unit toward the user to form an image on a target side. A compensating plate is disposed along the light path of the housing together with the reflective mirror and passes through the light rays coming from the target to be directed toward the user. The compensating plate is configured to suppress or minimize one or more movements of the image of the target caused by one or more movements of the dot sight device.