Aimpoint vs Eotech Magnified.

[Big Boy]

I am looking for some optics to put on my AR. It's 6.8 SPC.

I have always thought Eotech with magnifier, but I am considering the Aimpoint with magnifier as well. I like ACOG's but I want the ability to switch back to a CQB sight.

Which are better in your experience? And how accurate is a magnified Eotech sight?

 

[kwelz]

Eotech optics are to busy, especially when magnified. It makes it very hard to focus past dot onto the target.

This is just my personal opinion but hey, you asked.

My Coyote gun has an M3 with a 3X mag on it. I had considered am Eotech but decidd not to for the above reason.

 

[benEzra]

A 3x magnifier behind an Aimpoint magnifies the dot as well as the background. The Eotech dot, on the other hand, is diffraction limited, so when you use a magnifier to magnify the background, the dot is not magnified. Hence, the effective size of the dot is 1 MOA with a Mk 1 eyeball behind it, 0.33 MOA with a 3x magnifier, 0.25 MOA with a 4x magnifier, etc.

As to the busy-ness of the reticle, the Eotech gets less busy when magnified, as the 65MOA ring gets pushed away from the center, which clears more space around the center dot.

Here's the basic Eotech reticle at 1x:



Some people find the dot-and-circle busy at 1x, and others find it clearer and faster than a simple dot, so basically see if you can try one and decide if you like it.

Here's another Eotech without and with magnification here; the camera is situated a bit far back, so it makes the reticle look a lot smaller in both pics than it actually appears to your eye. This one (I think a model 557) has the more complicated reticle with multiple aiming dots (0-300, 400, 500, 600 meters) instead of the single-dot-and-ring, but even this one isn't too busy under magnification IMO.



...and here it is with a 3x magnifier behind it:

 

[RatDrall]

Wow, informative thread. Thanks!

 

[Fremmer]

Thanks for the pics. Wow, that magnifier sure does make a difference!

 

[GunnyHighway]

my advice would be to go someplace that stocks them and examine them both in person before you drop that much Green

 

[GunnyHighway]

my advice would be to go someplace that stocks them and examine them both in person before you drop that much Green IMHO

 

[jeepguy]

i really like these eotech's. do you find the aiming dots are necessary with only 3x magnification? i like how you showed the contrasting images with & without the magnifier, as it really clarified the differences for me.

 

[benEzra]

do you find the aiming dots are necessary with only 3x magnification?

The multiple dots for different distances, you mean?

http://www.eotech-inc.com/product.php?id=8&cat=1

It really depends on how far you typically will be shooting. If almost all of your shooting is going to be at less than 400 meters/440 yards, the multi-dot reticle doesn't make much sense, since you use the top dot for those ranges anyway. Here's the iSnipe trajectory for a 55gr .223/5.56x45mm at 3000 ft/sec, ballistic coefficient 0.243, at 75 degrees Fahrenheit, zeroed at 50 yards for a 225-ish far zero:

Yards................Point of Impact
5 yards....................2.5" low (use the bottom of the ring to aim)
10 yards...................2.2" low (use the bottom of the ring to aim)
15 yards...................1.9" low
20 yards...................1.6" low
25 yards...................1.3" low
30 yards...................1.0" low
40 yards...................0.5" low
50 yards...................right on
75 yards...................1.0" high
100 yards..................1.7" high
125 yards..................2.1" high
150 yards..................2.2" high
175 yards..................1.9" high
200 yards..................1.2" high
225 yards..................0.1" high
250 yards..................1.5" low
275 yards..................3.5" low
300 yards..................6.0" low
350 yards.................12.8" low
400 yards.................22.2" low
450 yards.................34.7" low
500 yards.................50.7" low
550 yards.................70.9" low
600 yards.................96.1" low
650 yards................126.9" low

You can see that out to 275 yards, you're still within 3.5" of the line of sight, and out to 350 you're within a foot of the line of sight. Even at 400 yards, a couple feet of holdover isn't that hard to estimate. If you had a multi-dot reticle, you'd still be using the topmost dot at those distances.

Where the multi-dot reticle really shines is at 500+ yards. Depending on your zero, the bullet is 4 feet low at 500 yards, 8 feet low at 600 yards, and almost 11 feet low at 600 meters/656 yards. Judging that degree of holdover is tricky, so once you get out in the 500-600+ yard regime, the extra dots are useful.

For myself, I went with the single-dot-and-circle Eotech 516, which is $90 to $150 cheaper than the multi-dot (but otherwise similar) model 557. Finances were (and are) tight with me, and since I personally don't have much occasion to shoot beyond 400 yards, the single-dot was a pretty easy choice. It's also less busy for close-range shooting than the multi-dot reticle would be.

A note about model numbers and such. Eotechs come in two basic flavors: (1) those that are set up for a lower-1/3 cowitness right out of the box, and (2) those that are set up for an absolute cowitness out of the box and need an aftermarket 7mm riser to do a lower-1/3. Within each of those two categories, some models have the capability to go ultra-dim for use with night vision equipment, and some don't (with NV capability jacking up the price quite a bit).

The following models are set up for a lower-1/3 cowitness out of the box, thanks to a built-in 7mm riser: Eotech 516, 517, 553, 556, 557. As far as I know, all other models (including 512, XPS series, etc.) are set up for absolute cowitness, so if you want a lower 1/3 cowitness you'll need a 7mm riser, like a LaRue QD mount.

Battery requirements are as follows:

• 516: two CR123, 1000hr runtime at brightness 12 (longer at lower settings)
• 517: two AA, 600hr runtime at brightness 12 with alkaline, 1000hr with lithium
• 553 (similar to 516 but with NV setting and QD base): two CR123, 1100 hours runtime at brightness 12
• 556 (similar to 516 but with NV setting): two CR123, 1100 hours runtime at brightness 12
• 557 (similar to 517 but with NV setting and multi-dot reticle): two AA, 600hr runtime at brightness 12 with alkaline, 1000hr with lithium

I prefer CR123 because they are physically shorter and allow me to run the same battery type in my optic and light. They don't cost any more than AA lithiums and are available at my local Walmart just like AA, so I don't really see much logistics advantage in using AA's.

The XPS series all run off a single CR123 battery and are set up for absolute cowitness (they need a 7mm riser to do a lower 1/3). The designations are as follows:

• XPS2-0 single dot in circle (traditional Eotech reticle), no NV setting
• XPS2-1 single dot only (no circle), no NV setting
• XPS2-2 two dots in circle, no NV setting
• XPS3-0 single dot in circle (traditional Eotech reticle), NV setting
• XPS3-1 single dot only (no circle), NV setting
• XPS3-2 two dots in circle, NV setting

Aimpoint model designations are a bit easier to understand. Basically, the CompM series has rubber armor and night vision settings, the CompC series does not but is considerably cheaper, and the Micro is a scaled-down model for light weight and small size (Micro T-1 has NV capability, Micro H-1 does not). You can get various models with 2 MOA, 3 MOA, and 4 MOA dots (I prefer as small as possible). All Aimpoints will need a riser to mount properly; LaRue Tactical makes some of the best Aimpoint mounts, but there are other players in the market as well.

 

[jeepguy]

thanks benezra, this is very inforative.

 

[Big Boy]

Thanks for all the info and pics. I won't be co-witnessing. Talk about busy... Irons are flip up in case of optic failure. So, to be used with a flip to side magnifier, should you go with the one that does, or does not have the riser?

 

[Lloyd Smale]

heres my opinion for what its worth. If i had a 6.8 and wanted to shoot long range and even hunt with it for about the same price as a aimpoint or eotech and a magnifier and all the mounts you can buy a acog. Much better optics and a much better long range sight and not enough slower at close range to make a diffence for any civilian

 

[Tirod]

Shooting long range with the 6.8 is a bit of a contradiction. It can be done, most shooters across the board don't shoot over 400. Having the capability is nice should it be needed, but it's a low percentage situation. If anything, the 3x would be the choice if it was coming up a lot, as would a lot of practice to be experienced on holdover.

My rambling point is if 600m is a common shot, a long range setup would be a better deal, including reconsideration of what the optimum caliber would be.

If it's truly a hunting rig, then shots are less than 200m most times, with 75m about the mean. Extra dots and magnification would be a potential hindrance for some. I'm also looking for a hunting optic for a 6.8, and as price is very much part of the situation, the combat optics are mostly out. NVG use won't happen. 600m is 98% excluded. Battery life is significant, but using a rechargeable AAA is a plus, I have them. Size and weight are important, but hunting with a 6.8 AR is already the advantage there. Since most shots in woodland are less than 100m, magnifiers are out.

That puts the bulk of my research into the $200 class of red dots recently released this year, which are all built in the same factory that also makes components for the two that the OP is comparing. The ones with integral mounts help keep the cost down more, and leaves just one for me that fits all the criteria as a AR optic dedicated to that one gun.

When you strip the combat level of redundant quality control, lack of seeing the red dot from the front, NVG use, and contract price support from the equation, the newer optics can fill the bill. After all, it's just a hunting gun, the difference in price can buy a lot of practice ammo, gas for the trip, or a Goretex hardshell. In really inclement weather, hunters can with serious rain wear, but 600m shots won't happen.

That's a frugal point of view, those that don't have to be can buy both.

 

[benEzra]

Thanks for all the info and pics. I won't be co-witnessing. Talk about busy... Irons are flip up in case of optic failure. So, to be used with a flip to side magnifier, should you go with the one that does, or does not have the riser?

I personally like a lower 1/3 cowitness with a flip-up rear. The front sight is low enough to be out of the way if you're looking through the center of the glass, but it's there if you need it in a hurry, and the rear is out of the way so it's not looming in your vision:

If you don't like the front sight there in your vision, though, then a flip-down front certainly is a viable option.

As to whether to go with a riser model or not, it probably depends more on whether you like the reticle with multiple aiming points, or not, because I *think* that reticle only comes with the 557, which has a built-in 7mm riser. What I would suggest is to pick what reticle you like (for beyond 400 yards the multiple dots do make a lot of sense), find out what Eotech models it's available on, see what kind of flip-to-side mount you need to put the magnifier at the same height as the optic (e.g., you'll need a flip mount 7mm higher for a 557 than for a 512 or an XPS), and then make sure you can fit them all (plus your rear sight of choice) on the rail space you have. I know for sure that the battery compartment on the 7mm riser models will clear the handguards or free float tube, but I dunno about the non-riser models. It'd be something you'd definitely want to check. Basically, you want to make sure that all your chosen stuff will work together before you buy it, rather than after...

 

[TonyAngel]

Before you go buying a red dot with a magnifier, you'd better go check them out. Yeah, the rig looks cool and a lot of guys rant and rave about them, but they aren't for everyone.

The setup of a red dot sight (escpecially an Eotech) and a magnifier is heavy. Really heavy. The eye relief on the magnifiers sucks too. I was hitting myself on the glasses all of the time when assuming odd shooting positions. I'd go for a TA33 3X ACOG any day over a red dot and magnifier combo.

Really, if you are going to be hunting with that rig and only need a short range optic, for the money you're gonna throw down on the optics and mounts, I'd get a Nightforce 1-4X scope. It might cost a little more but it will be far superior in terms of optical quality. It's probably going to weigh less too.

 

[RX-178]

There is one problem with the Eotech when used with a magnifier. Eotech has done a very good job in addressing it, but it still exists.

You CANNOT use a magnifier with an Eotech if the magnifier mount is not adjustable for windage and elevation. It sounds silly, since the Eotech is actually the aiming device, but it's true.

The Eotech reticle is generated inside the device, and reflected up off of a mirror in the front, then reflected again off of a mirror at the top of the device. The image that your brain translates into an aiming reticle is actually coming back towards your eye at an angle.

This means that the magnifier has to be adjusted to match the angle of the light in order to catch the reticle and magnify it.

So, magnifiers will still WORK with an Eotech, but you can't use any form of inexpensive scope ring to mount the magnifier. It has to be the actual expensive, complicated Eotech-labeled mount with the windage and elevation adjustments.

The Aimpoint on the other hand, has none of these problems. Any magnifier mounted behind it will pick up the dot as long as it's at the right height off of the rail.

 

[jmorris]

This is the best thing I have come up with when you have to switch from 10 yards to precision shooting at 300 instantly, like in a 3-gun match. Both are designed and good for their job and cost less than anything discussed so far. Most importantly you don’t have to jack with anything to use either, same cheek weld and everything.

 

[benEzra]

There is one problem with the Eotech when used with a magnifier. Eotech has done a very good job in addressing it, but it still exists.

You CANNOT use a magnifier with an Eotech if the magnifier mount is not adjustable for windage and elevation. It sounds silly, since the Eotech is actually the aiming device, but it's true.

The Eotech reticle is generated inside the device, and reflected up off of a mirror in the front, then reflected again off of a mirror at the top of the device. The image that your brain translates into an aiming reticle is actually coming back towards your eye at an angle.

This means that the magnifier has to be adjusted to match the angle of the light in order to catch the reticle and magnify it.

So, magnifiers will still WORK with an Eotech, but you can't use any form of inexpensive scope ring to mount the magnifier. It has to be the actual expensive, complicated Eotech-labeled mount with the windage and elevation adjustments.

The Aimpoint on the other hand, has none of these problems. Any magnifier mounted behind it will pick up the dot as long as it's at the right height off of the rail.

I believe this is incorrect. The image you see in an Eotech is most definitely coming straight back, as the last thing the beam hits is a diffraction grating laminated inside the back glass. Here's the patent with a diagram:

http://www.freepatentsonline.com/6490060.pdf

The light that constitutes the reticle is perfectly parallel coming out the back of the sight, which is one way an Eotech differs from a cheap non-holographic red dot (it is even marginally more parallel than an Aimpoint, which uses a compound lens to flatten the wavefronts). AFAIK, Eotech magnifers and the mounts normally used with them are not adjustable for windage or elevation, and there is no reason they'd need to be.

http://www.brownells.com/1/1/893-holographic-sight-g23-fts-magnifier-g23-fts-magnifier-eotech.html

One of the selling points of the Eotech is that it is not particularly sensitive to magnifier placement:

http://www.dtic.mil/ndia/2004armaments/DayII/SessionII/05Gallagher_SmallArms_Sight_Oppurtunity.pdf

Holographic sight provides true point source as aim point

• Dot size limited only by eye resolution to 1 m.o.a.
• Placing 4X scope behind sight magnifies target scene 4X but dot size remains 1 m.o.a.
• Effective dot size is 0.25 m.o.a. or 1 “ at 400 yards
• Aiming dot provided by holographic sight, placement of magnified scope not critical

I know of no reason whatsoever why any magnifier wouldn't work with an Eotech as well as it does for an Aimpoint, as long as you can align the magnifer with the center of the Eotech's lens (and it should work fine off-center as well, but you may block part of your field of view).

 

[RX-178]

Well, the reticle is coming back straight ENOUGH for your eye to see, but just from a mathematical point of view, if it were coming back perfectly straight, the reticle would have to be reflecting off of the front window of the optic, and it most certainly is not. If it were, Eotechs wouldn't function with the front window broken, and they do.

From Eotech's own website ( http://www.eotech-inc.com/products.php?id=3 )

'The magnifier mount provides elevation and azimuth adjustment to allow the reticle to be centered in the FOV of the magnifier'

Like I said, the Eotech reticle reaches your eye after reflecting of of a mirror at the top of the device. That means that it is most definitely coming back at a slight downward angle. It HAS to come back at a slight downward angle, unless you have some kind of miniature gravity well in the device to bend the beams of light in mid-air.

The Aimpoint dot comes back directly off of the front window, so it DOES come straight back. A magnifier mount would not need an azimuth and elevation adjustment for that.

 

[FLAvalanche]

I have an eotech with a cheap magnifier behind it that does not have azimuth and elevation adjustments and it works just fine.

Considering I've been hitting clays at 200 yards with that setup is enough to convince me you don't need adjustments on the magnifier.

 

[benEzra]

Well, the reticle is coming back straight ENOUGH for your eye to see, but just from a mathematical point of view, if it were coming back perfectly straight, the reticle would have to be reflecting off of the front window of the optic, and it most certainly is not. If it were, Eotechs wouldn't function with the front window broken, and they do.

You are completely incorrect, because the Eotech reticle is projected by diffraction gratings, not mirrors. The projected light is indeed perfectly parallel (arguably even more so than the Aimpoint's, which is itself darn good); it is not a reflection, it is a synthetic wavefront.

You can certainly incorporate an adjustable mount to allow the reticle to be perfectly centered in the magnifier--just as you can with an Aimpoint--but the Eotech doesn't need that any more than the Aimpoint does. If you use a cheap mount that puts the center of the optic's lens off-center in the magnifer, the effect is nil, other than having your magnifier off-center.

FWIW, the Eotech will function with both windows broken. As long as there is a fragment of the diffraction grating in the rear glass laminate to look through, you will see the reticle in that fragment if you line your eye up with it.

 

[RX-178]

This diagram has been the bane of my existence in the optics field. It implies that the diffraction grating is angling the light that forms the reticle in a perfectly straight line back to the eye.

Diffraction, by definition, means that the light is not a straight beam, is being spread apart along different angles.

Your eye is catching the diffracted pattern, and your brain translates that into the image of a reticle.

If the objective lens of your magnifier doesn't catch the entire pattern, your eye and brain can't interpret the light as being a reticle. This is incidentally why the dot size doesn't change when magnified, while the size of the reticle around it does.

 

[Destructo6]

'The magnifier mount provides elevation and azimuth adjustment to allow the reticle to be centered in the FOV of the magnifier'

It's not necessary to center the reticle in the magnifier. It looks better, but it is not necessay. At least that's what the instructions said.

I didn't notice a difference in the appearance of the reticle when going from the adjustable Eotech-made mount to the Larue flip to side mount.

 

[benEzra]

It implies that the diffraction grating is angling the light that forms the reticle in a perfectly straight line back to the eye.

That diffraction grating laminated to the back glass isn't just any diffraction grating, it's a hologram. Just like this one:



That hologram was originally constructed like this:

..and the reconstructed wavefront is a perfect replica of the original wavefront. That's what holograms do.

If instead of the a cube at close range, you create the hologram using a projection of a diffraction-limited on-axis point source at optical infinity surrounded by a 65-arcminute ring, as shown on frame 6 of this document from the Defense Technical Information Center...

http://www.dtic.mil/ndia/2004armaments/DayII/SessionII/05Gallagher_SmallArms_Sight_Oppurtunity.pdf

and then you shine a laser at the resulting diffracting grating at the same angle and same wavelength used to record it, you get a virtual image of the reticle that is projected in the same direction as the light from the original reticle image used to produce the grating. Again, that's what holograms do. In the cutaway that you posted, the light coming off the mirror system is the reconstruction beam, the inside of the back glass is the hologram, and the collimated light coming straight and parallel out the back is the reconstructed wavefront of a point source at optical infinity, i.e. the center dot.

Now it is true that the wavefront of the dot-and-ring reticle is much more complex than a bunch of perfectly parallel rays---no argument there, as parallel rays only describe the image of the center dot (I guess I should have said so upthread)---but the virtual image produced is absolutely parallel to the sightline, giving unlimited eye relief and allowing off-axis magnifier positioning without any problems. The DTIC presentation even says that explicitly, listing one of the advantages of the holographic sight as "placement of magnified scope not critical."

And yes, if you back up so far that the rear window subtends less than 65 arcminutes as seen from your position (this would be several feet), then you won't see the outer ring unless you move your head around, but you will see the on-axis center dot no matter how far you back up, even from 20 or 30 feet.

If the objective lens of your magnifier doesn't catch the entire pattern, your eye and brain can't interpret the light as being a reticle. This is incidentally why the dot size doesn't change when magnified, while the size of the reticle around it does.

I just got out my 516 and checked. I verified over twenty feet of eye relief straight behind the rifle (longest sightline I have at the moment, with the rifle laying on a box in the hallway and me backed up against the living room wall), with the center dot still centered on the front sight post (the dot was still easy to catch at that distance). I also tried blocking off the entire back glass except for a ~1/4" x 1/4" square at a bottom corner of the glass, and you can still see the dot (and you'd still hit, if you were shooting at a target).

This is the patent that covers the holographic projection mechanism.

http://www.freepatentsonline.com/6490060.pdf

If you are indeed in the field of diffraction optics, read this. It will be clear (and you may think "why didn't I think of that"...it is a very elegant design).

 

[amprecon]

A 3x magnifier behind an Aimpoint magnifies the dot as well as the background.

Is this true? So a 2moa dot on a Comp series, when seen through the Aimpoint will actually become 6moa?