EOTech's Holographic Sight
January 03, 2011
The EOTech HWS is a modern nonmagnified firearms sight.
The EOTech HWS is a modern nonmagnified firearms sight.
A nonmagnified optical sight that is steadily growing in popularity is the Holographic Weapon's Sight (or simply HWS) from EOTech, Dept. ST, 2600 Green Court, Suite 400, Ann Arbor, MI 48105; 734-741-8868; www.eotech-inc.com. Designed to provide a bright, easy-to-see aiming point to facilitate rapid shot placement, the EOTech HWS is not simply a run-of-the-mill red-dot sight. Rather, it's totally different and generates its illuminated reticle through the use of holography.
For those of you not familiar with holography, it is in simplest terms the process of producing visual images through wavefront reconstruction. Invented in 1962 by Juris Upatnieks and Emmett Leith at the Environmental Research Institute of Michigan (ERIM), these projected images (called holograms or holographs) may be two- or three-dimensional. ERIM was conducting (and still conducts) research and development for the U.S. Department of Defense, NASA, and members of the intelligence community, and they were soon working on a military application for this technology.
In the late 1970s it was used aboard helicopter gunships, and in the 1980s it came into its own in the heads-up display of jet fighter aircraft. Eventually the technology was reduced in size to the point where it can now be employed practically on small arms.
The HWS unit bears no resemblance to a conventional optic. There is no round tube to look through, no turrets to spin. Instead, it is a radical-looking optic that is rectangular in shape. Positioned at the top rear of the unit's body is a rectangular lens assembly that you aim through. It is constructed from three layers of laminated, shatterproof, scratch-resistant glass that's 3/16 inch thick and features antireflective coatings.
The body of the optic is made from a tough lightweight synthetic material. The display window portion of the housing is protected by a .10-inch-thick extruded aircraft-grade aluminum shroud. Rather than abutting directly against the housing, there's a 1/16-inch gap between the shroud and housing to absorb any extreme shocks.
The front of the HWS houses the batteries that power it and is opened via a lever. Rotating the lever up and forward allows the entire battery compartment to be removed to change batteries. Models are available that are powered by either the short 1.5V N alkaline batteries or by standard AA batteries. Battery life is listed as up to 1100 hours on the AA model, but it's quite a bit less from a practical standpoint. If battery life is less than 20 percent at start up, the reticle will blink for five seconds to alert the operator.
On the right side of the HWS's housing are the windage and elevation adjusting screws for zeroing the sight. These are uncapped and provide 1/2 MOA adjustments in fairly distinct clicks. No tool is required for zeroing; the slots in the adjusting screws are wide enough to accept either the rim of a cartridge or a coin. The bottom of the unit features an integral base that is designed to mount directly onto a standard Weaver or Picatinny rail. The optic is locked in place on the gun via one crossbolt.
The face of the unit features two--or three, depending upon the model--push-button controls. Standard models feature one button with an "Up" arrow and one button with a "Down" arrow. Military/LE models also have a night vision (NV) button located between the two standard buttons. To turn on the unit you simply push either of the buttons. If the Up arrow is used to turn the unit on it will automatically shutdown eight hours after the last push button control is utilized. If the Down arrow is used, it will automatically shut down after four hours. This automatic shutdown feature prevents accidentally leaving the unit on and killing the batteries. The HWS features 20 brightness control settings to cover a wide range of lighting situations.
When the unit is turned on, the default setting is Level 12. The Up and Down buttons increase or decrease the reticle's intensity to suit the user's requirements. The NV button drops the reticle's intensity to the night vision spectrum. Doing so allows a night vision device (NVD) to be used in conjunction with the HWS for engaging targets in total darkness. Ten brightness settings are available in night vision mode.
This provides significant latitude for variances in individual NVDs, eye sensitivity from person to person, and operating conditions. One nice feature of the NV setting is that there is no visible muzzle side light signature. This means the bad guys can't see any light projected from the front lens as is possible with a reflex sight. To switch back to daylight mode you simply depress the NV button again. To turn the HWS off push both arrow buttons simultaneously.
The result is a rugged sight that weighs less than nine ounces and is simple to operate.
What you see when you turn the HWS on is a reticle that appears on the same plane as the target. The HWS is not simply projecting a dot. Unlike a reflex sight that can only create a parallax-free dot, laser holography can create multiple objects in two or three dimensions. In the case of the HWS a circle 65 MOA in diameter is projected. Located at 12, 3, 6, and 9 o'clock are tick marks to prevent canting. In the center of the circle is a fine, 1 MOA dot. This combination of a large circle and a fine dot allows for both very rapid target engagement and precision work.
If the reticle is smaller than the target, put the reticle on the target and fire. If the target is smaller than the reticle, center the target in the circle and fire. Doing so provides very rapid hits. If greater precision is required, slow down and use the small central aiming dot. Also, as the unit is parallax-free the shooter's head and eye alignment are not an issue. As long as the shooter can see the reticle on the target, through any portion of the display window, he'll hit it. This is true even if the window is broken and part of the lens is missing.
Over the years I've used EOTech's HWS on a variety of submachine guns, assault rifles, and even belt-fed GPMGs. In doing so I've found this optical sight excels at shooting on the move, from awkward positions, at moving targets, and in poor lighting. From point blank to 300 meters the HWS works extremely well. The field of view (FOV) is huge, peripheral vision is unimpaired, and color rendition and light transmission are extremely good.
The HWS is not perfect. My main gripes are that with heavily gloved or mittened hands the buttons can be difficult to feel and depress. I would also prefer a quick detachable (QD) mount rather than the crossbolt. And I would like to see longer battery life. In EOTech's defense it h
as been hard at work making improvements. The buttons have been vastly improved, and battery life is now significantly longer.
The EOTech HWS comes into its own engaging multiple targets while on the move.
Regarding my desire for a QD mount, there are two very good options available. LaRue Tactical (Dept. ST, 850 CR 177, Leander, TX 78641; 512-259-1585; www.laruetactical.com) produces a dedicated EOTech HWS base. The sight is crossbolted onto this 4.75-inch-long riser block. It then attaches onto a MIL-STD 1913 rail. On the left side of the base is a rotating QD lever that allows the mount to be instantly removed or attached.
When mounted onto an AR15 platform the mount raises the optic just high enough to allow iron sights to co-witness through the lower one-third of the FOV. At the rear of the base is a short length of MIL-STD 1913 rail section, allowing an NVD to be mounted directly behind the optic. LaRue Tactical's mount is simple, rugged, and works well; list price is $119.
Another option I have been using for the past few months is the new Accucam from GG&G, Dept. ST, 3602 E. 42nd Ave., Tucson, AZ 85713; 800-380-2540; www.gggaz.com. A rotating side lever that installs directly onto your EOTech HWS in place of the factory crossbolt, the Accucam makes your HWS quick detachable.
The Accucam is easy to install and locks your HWS securely to your firearm. If you need to remove it, simply rotate the side lever to the rear. The optic is then released from the gun's rail. In a word, the Accucam is slick and something to consider if you own an EOTech. It lists for $84.95.
Looking for a nonmagnified sight for use from spitting distance to 300 or so yards? Consider the EOTech HWS. While unconventional looking, it offers impressive performance in a rugged package. Suggested retail prices range from $299 to $459, depending upon the model.