A little known, but curious, use of a hologram’s ability to reconstruct an image as if it were ‘floating’ in space, is for holographic rifle sights. So how does this relatively new type of aiming system work and what are the advantages and disadvantages?
Holographic sights are a type of gunsight that use lasers to create a reticule that appears to ‘float’ in front of the weapon in the user’s field of view. They work by illuminating a reticule image stored on holographic film within the window, creating a precise image. By creating a reconstructed image rather than simply projecting a LED dot or crosshair onto a pane of glass, they ensure that the image is unaffected by things like astigmatism, magnification, and even a cracked objective lens. The sight adjusts for wind and elevation by tilting the holographic grating, and the brightness is adjusted by raising or lowering the intensity of the laser.
If you use a standard sight, you’ll have to position the scope in a way that the reticule can be atop the observed target. Those aims look for the ideal placement of your head. If you move only a bit, the reticule and the rifle won’t point at the same position. The main advantage provided by holographic sights is that they allow you to lock the reticule in the desired position. That way, the sight moves if you tilt the rifle but remains aimed at the spot.
The major components of holographic sights include a collimating reflector, laser diode, holographic grating, a reticule image hologram, and the holographic image 1.
Exceptional field of view – holographic sights offer a field of view that’s larger than other comparable devices.
The dot size remains the same regardless of the magnification – if the magnification option is used, the dot size doesn’t change.
Excellent accuracy – once the reticule is locked, it stays on target. Even if the rifle or your head is moved, it will not affect the accuracy.
Suitable for professionals and novices – newcomers will appreciate how easy it is to achieve good accuracy while experienced users will benefit from the convenience and precision, even in harsh environments.
The units are rugged – continuing to operate with a shattered or partially obstructed sight window.
It lacks an etched reticule – which some users might find off putting.
Price – an average holographic sight will probably cost more than other aims.
Whilst many readers of Holography News® might feel a bit uneasy about the application of holography to improving the precision of firearms, we have to accept that all technology advances will come under scrutiny from the military to assess their battle potential.
Further, the industry has to acknowledge that military applications have played a significant, and continuing role, in advancing the technology 2.
1 - https://theoptics.org/how-do-holographic-sights-work/.
2 - https://jennthepr.com/holographic-technologies-and-military-applications/.
