EOTech Holographic Sights Explained: How They Work

An EOTech holographic weapon sight (HWS) uses a laser diode, not an LED, to light a hologram of the reticle recorded in the sight's window, so the reticle appears to sit out on the target rather than on the glass. The standard EOTech reticle is a 68 MOA ring around a 1 MOA dot: the ring for fast close-range aiming and the dot for precision. The main trade-off against an LED red dot is battery life, which EOTech rates at 1,000 hours on one CR123 against tens of thousands of hours for many LED dots.

This guide explains how the technology works, what the model and reticle codes mean, how the magnifiers fit in, and when an EOTech is the right choice over a conventional red dot.

How a holographic sight works

A conventional red dot sight shines an LED onto a coated lens, which reflects a dot back to your eye. A holographic sight works differently. A hologram of the reticle is recorded into the viewing window when the sight is made, and a laser diode reconstructs it when you switch the sight on. EOTech says that because the HWS is "powered by a laser diode instead of an LED", it offers "the smallest aiming point in the industry", and that the reticle is "perceived by the shooter to be projected at the target".

In practice that gives three advantages:

• A detailed reticle. The ring-and-dot, the ballistic "-4" reticle and the Danger Close Reticle would be difficult to produce with a single LED.
• Unlimited eye relief. Like any 1x sight, it works at any distance from your eye, so you can mount it anywhere along the rail.
• Tolerance of a damaged window. EOTech states that even when the window is "partially shattered or obscured by snow or mud", the sight keeps working.

EOTech also says its design "inherently minimizes the visual effects of parallax". That is a claim of minimal parallax, not zero parallax, so a consistent head position still helps.

The 68 MOA ring and 1 MOA dot at distance

MOA is an angle, so what the reticle covers depends on range. One MOA is 29.1 mm at 100 m.

Up close, the ring is what you use: put it on the target and fire. At distance, the 1 MOA dot is small enough for precise shots. For more on these units, see our MOA at distance chart.

Decoding the EOTech range

The model name tells you the features, and the number after the dash tells you the reticle. These are the models we stock, with specifications from EOTech's own product pages:

All four use a single CR123 battery and have 20 daylight brightness settings. EOTech rates battery life at 1,000 continuous hours at setting 12 at room temperature, or 600 hours for the green-reticle versions.

Reticle codes

• -0: 68 MOA ring with a 1 MOA dot, the classic EOTech. For example, the EOTech EXPS3-0 and the XPS2-0.
• -1: a single 1 MOA dot with no ring.
• -2: 68 MOA ring with two 1 MOA dots, one above the other.
• -4: 68 MOA ring with four 1 MOA dots, a ballistic reticle that EOTech designs for 5.56 NATO/.223.
• DCR: the Danger Close Reticle, a 68 MOA ring with a cut-out at the top and a chevron.

Holographic vs LED red dot

Both are 1x, both are fast, and both work with both eyes open. The differences that matter are practical:

• Battery life: 1,000 hours for an EOTech against, for example, 40,000 hours for the SIG ROMEO5 Gen II and 50,000 hours for Holosun's HS510C, according to their makers. EOTechs have a user-set auto shut-off of four or eight hours, so they must be switched on when needed.
• Weight and size: an EXPS3 weighs about twice as much as a compact 1x20 red dot.
• Reticle: the holographic reticle is more detailed, and some shooters with astigmatism find it crisper than an LED dot. That varies from person to person; see our astigmatism guide.

For a wider comparison, including LPVOs, read red dot vs holographic vs LPVO.

Adding a magnifier

EOTech's magnifiers sit behind the sight on a switch-to-side (STS) mount, so you can swing them out of the way for 1x. EOTech gives these figures:

• G33: 3x, eye relief 2.2 in (55.9 mm), 7.3° field of view.
• G43: 3x, eye relief 2.5 in (63.5 mm), 7.5° field of view; EOTech calls it "a miniaturized version" of the G33.
• G45: 5x, eye relief 2.6 in (67 mm).

EOTech states that its 1 MOA dot stays 1 MOA with a magnifier in place, while "the target gets 3-5 times bigger". A sight and magnifier sold together is a Holographic Hybrid Sight: the HHS VIII, for example, pairs an EXPS3-0 with a G33. Browse EOTech magnifiers, and read our guide to choosing a red dot magnifier for 3x vs 5x.

Is an EOTech right for you?

Choose an EOTech if you want the fastest reticle pick-up at close range, a detailed reticle and the option of a matched magnifier, and you do not mind changing a battery more often. Choose an LED red dot if battery life, weight and cost matter more. Compare both in our holographic sights and rifle dot sights collections.

Frequently asked questions

What is the difference between a holographic sight and a red dot?

A red dot reflects an LED off a coated lens; a holographic sight uses a laser diode to reconstruct a hologram of the reticle recorded in the window. The holographic reticle can be more detailed, but battery life is much shorter.

How long does an EOTech battery last?

EOTech rates the XPS and EXPS models at 1,000 continuous hours on one CR123 at brightness setting 12 at room temperature, or 600 hours for green-reticle models. Higher settings and cold weather reduce it.

What is the difference between the EXPS2 and EXPS3?

The EXPS3 adds 10 night-vision brightness settings and is rated waterproof to 10 m, against 3 m for the EXPS2. Both have a quick-detach lever.

Can you add magnification to an EOTech?

Yes. A G33 or G43 (3x) or G45 (5x) on a switch-to-side mount sits behind the sight and swings aside for 1x use.