| Holographic weapons sights have become increasingly | | | | sight up or down, or left or right, the sight is |
| popular with shooters, as they give the shooter the | | | | reconstructing the view instantly. OK, you say, but how |
| ability to quickly lock in on target, even if the shooter's | | | | does the reticle move and stay on target? The reticle |
| head position is not aligned with the sight. With a | | | | is actually a laser beam that's being projected onto |
| conventional optical scope, a shooter must have his | | | | that same clear window within the sight. A reticle |
| eye aligned with the scope in order to place the reticle | | | | mask defines the shape of the reticle. The mask may |
| over the target. If the shooter's head isn't perfectly | | | | be a dot, a triangle, a circle, or whatever other shape |
| aligned, the scope's reticle isn't pointing to the same | | | | the manufacturer offers. When the holographic sight is |
| spot on the target as the gun. With a holographic | | | | attached to the gun, the laser beam is projected along |
| ("holo") sight, the reticle is always on the spot on the | | | | the same axis as the gun. Thus, when you move the |
| target where the weapon is pointed. Move the gun left | | | | muzzle of the gun to the left, the projected reticle |
| or right, and the reticle moves as well, but is still on the | | | | image on the clear window moves to the left on the |
| point of aim. How is this possible? Unlike the view you | | | | same axis. Up, down, left, right: the reticle image is |
| see through a conventional scope, what you are | | | | always following the direction of the muzzle. So, when |
| seeing through a holographic sight is not real. It's a | | | | you look through a holographic sight, you're actually |
| reconstruction of the view. What's more, the reticle | | | | seeing two things: the projected view of the target |
| that you see is not actually in the sight, but is a | | | | area, which changes as you move the sight; and the |
| projection of a reticle image. Before you start | | | | projected reticle, which moves along with the axis of |
| scratching your head, think about watching a movie. | | | | the gun. The result of this combination is that, as long |
| The movie camera has recorded the the light reflected | | | | as you can see the view of the target area through |
| from the objects in a scene onto film. When the film is | | | | the sight, and as long as you can see the reticle, you |
| projected onto a movie screen, you see the scene | | | | can get your gun on target. The laser reticle is |
| that was originally recorded. The process of | | | | essentially performing the same function as a laser |
| holography involves reconstructing the light waves that | | | | sight, except that the laser is projected onto the clear |
| are reflected from an object. What we commonly call | | | | window, and not onto the target itself. This offers |
| "light" is a spectrum of waves. The holographic sight | | | | several advantages, one of which is that the laser |
| encodes the wave patterns reflected from the view | | | | beam is not visible to anyone but the shooter. Another |
| of the target area, and projects these wave patterns | | | | advantage is that most holographic sights allow the |
| onto a clear window within the sight. The projected | | | | user to vary the brightness level of the laser reticle, |
| wave patterns are then illuminated by a laser, which | | | | while the dots from laser sights may be hard to see |
| reconstructs the wave patterns. The result is a | | | | on the target in bright sunlight. With advances in |
| three-dimensional image of the view of the target | | | | technology, holographic sites have become more |
| area. Unlike a film, though, the holo sight is recording | | | | compact and more affordable, thus leading to their |
| and then projecting the light waves in real time onto | | | | increased popularity with the shooting community. |
| the clear window within the sight. As you move your | | | | Richard A. |