Effect on POI when occluding red dot sights

A few posts recently have brought up how phoria will negatively impact POI when shooting with occlused RDS'. Some of the benefits of shooting with a covered RDS include the inability to wash out the dot when using a weapon light or changes in ambient lighting, maintaining a target focus vs dot focus, and allowing the use of an IR light along with an RDS when aiming under NODs (especially useful with pistols).

Molon did testing with a TA11 3.5x ACOG and documented a significant POI shift at 25y. For today, I only had access to a 25y indoor range. With an 11.5" rifle topped with a T2 in LaRue LT660 mount, I fired a quick 10-round group offhand with the RDS uncovered (left target), then closed the solid cover and fired another quick offhand 10rd group (right target). The rifle is zeroed at 200y and POA remained consistent at the center of the B8.

https://i.imgur.com/1rRlHoi.jpeg

While there is some shift in POI, it is insignificant within CQB distances. I will have access to a 200y range next week and will test on paper and steel at various distances to continue gathering data.

Additionally, I repeated this with a Glock 19 and Holosun HS507c X2. Both were 5 round groups at 25y shooting 124gr Geco 9mm. The top target is with the RDS taped, the bottom is uncovered.

https://i.imgur.com/rlhBwoz.jpeg

Interestingly, there was no perceptible difference in POI. This could be attributed to the fact that I normally zero my pistols offhand with both eyes open, so I'm already accounting for any effects of phoria.

I'm planning to also test this with a 4x ACOG, 1-6x Razor at 1x/3x/6x, and to stretch the RDS' legs to see how far it can effectively be used while covered.

Interesting ideas. If I remember to try this, I can do it on our IPSC sized steel with an Aimpoint at 400 and/or 500 yards next range trip.

Great work; thanks.

I find its utility to be most exploited in CQB-type shooting (home defense being my personal reason). However, I'm assuming you shoot a lot against very bright target backdrops, such as in a desert, and can see this being potentially useful in bright sunlight.

Academic curiosity is the sole reason I'm going to test it at longer distances. I'm curious how the Razor will do across the magnification range...if occluded, it shouldn't make a significant difference between 1x and 6x, but the targets will tell the tale.

It is a parallax problem, I think. Red dot is supposed to do better. The real holographic sight (eotech?) should have none.

Scope sight, acog included, always has parallax other than the set distance. However it isn't a problem if the shooter's eye is always coaxial to the optics. Phoria makes the eye deviate. The shooter needs to consciously adjust for that. The black ring around the view must be kept even and symmetrical all around.

-TL



Sent from my SM-N960U using Tapatalk

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Originally Posted by GTF425

I find its utility to be most exploited in CQB-type shooting (home defense being my personal reason). However, I'm assuming you shoot a lot against very bright target backdrops, such as in a desert, and can see this being potentially useful in bright sunlight.

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Yes. Agreed. This would be more for the curiosity factor. Stretching out to 400 plus would hopefully show any large POI shifts. I'd really have to get on the gun with the cap closed to see if it would be a fair test... I've never sighted a target that far with the cap shut.

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Originally Posted by GTF425

A few posts recently have brought up how phoria will negatively impact POI when shooting with occlused RDS'. Some of the benefits of shooting with a covered RDS include the inability to wash out the dot when using a weapon light or changes in ambient lighting, maintaining a target focus vs dot focus, and allowing the use of an IR light along with an RDS when aiming under NODs (especially useful with pistols).

Molon did testing with a TA11 3.5x ACOG and documented a significant POI shift at 25y. For today, I only had access to a 25y indoor range. With an 11.5" rifle topped with a T2 in LaRue LT660 mount, I fired a quick 10-round group offhand with the RDS uncovered (left target), then closed the solid cover and fired another quick offhand 10rd group (right target). The rifle is zeroed at 200y and POA remained consistent at the center of the B8.

https://i.imgur.com/1rRlHoi.jpeg

While there is some shift in POI, it is insignificant within CQB distances. I will have access to a 200y range next week and will test on paper and steel at various distances to continue gathering data.

Additionally, I repeated this with a Glock 19 and Holosun HS507c X2. Both were 5 round groups at 25y shooting 124gr Geco 9mm. The top target is with the RDS taped, the bottom is uncovered.

https://i.imgur.com/rlhBwoz.jpeg

Interestingly, there was no perceptible difference in POI. This could be attributed to the fact that I normally zero my pistols offhand with both eyes open, so I'm already accounting for any effects of phoria.

I'm planning to also test this with a 4x ACOG, 1-6x Razor at 1x/3x/6x, and to stretch the RDS' legs to see how far it can effectively be used while covered.

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The best way to test this is to look at the target, and only get behind the optic for a quick sight picture.IME the longer you sit occluded the more phoria impacts you.

People do this in uspsa comps while training themselves and still place top 5 or win. I would not do it for precision work (sitting behind the sight), but for reactive- mid or fast paced shooting it should be fine for a/c zone hits to decent distsnce... hell ive hit 8" targets consistently at 60 with no sights on a rifle, occluded would be much better.

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Originally Posted by MegademiC

The best way to test this is to look at the target, and only get behind the optic for a quick sight picture.IME the longer you sit occluded the more phoria impacts you.

People do this in uspsa comps while training themselves and still place top 5 or win. I would not do it for precision work (sitting behind the sight), but for reactive- mid or fast paced shooting it should be fine for a/c zone hits to decent distsnce... hell ive hit 8" targets consistently at 60 with no sights on a rifle, occluded would be much better.

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I'm doing it because there were tenured members claiming that you'll be 12" plus off target at 25y if you use an occluded sight.

I am 100% confident that's not true, but am gathering the necessary target data to support the hypothesis. I'm mostly curious to see how far it can be pushed more than anything. Magnified optics are coming later this week.

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Originally Posted by GTF425

I'm doing it because there were tenured members claiming that you'll be 12" plus off target at 25y if you use an occluded sight.

I am 100% confident that's not true, but am gathering the necessary target data to support the hypothesis. I'm mostly curious to see how far it can be pushed more than anything. Magnified optics are coming later this week.

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I don't think anyone has said that everyone would be 12" off target at 25 yards if you use an occluded sight, but instead that it is possible for some individuals to be that far off. Some folks can absolutely do good work using occluded sights. Others will struggle. While I applaud your attempts to gather data, they're nothing more than n = 1, and thus don't really say anything outside of the fact that occluded sights work pretty well for an unknown percentage of folks.

Saves me the hassle of possibly encouraging others to try something new. Carry on with our regularly programmed budget LPVO threads.

Meh. I still would like to try it. I actually was glassing small objects in my house the other day to try to simulate a sight pic on a 300-400 yard target since we haven't been out to the range in a few weeks. Looks like it's doable at distance if you slow down and focus.

For CQB use, if you want the benefit of a constant brightness setting of a red dot and occluded is a good solution for you, just zero with the sight occluded and leave it that way. You now have the ability to move through different lighting and leave the dot alone. Verify at range in case the situation changes. Or forget it and move on.

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Originally Posted by Uncas47

For CQB use, if you want the benefit of a constant brightness setting of a red dot and occluded is a good solution for you, just zero with the sight occluded and leave it that way. You now have the ability to move through different lighting and leave the dot alone. Verify at range in case the situation changes. Or forget it and move on.

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This would potentiallu allow for a *lower brightness setting and longer battery life, as well. The dot is against a black background.

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Originally Posted by GTF425

I'm doing it because there were tenured members claiming that you'll be 12" plus off target at 25y if you use an occluded sight.

I am 100% confident that's not true, but am gathering the necessary target data to support the hypothesis. I'm mostly curious to see how far it can be pushed more than anything. Magnified optics are coming later this week.

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I ran an Armsen OEG onna (.223) Galil in (very) early 3 gun for a while.
Was not difficult to keep hits in A/C zone at 200 yds.
This under Field/Timed conditions. 12” @ 25 yds margin of error at 25 yds is ridiculous.

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Originally Posted by JediGuy

This would potentiallu allow for a *lower brightness setting and longer battery life, as well. The dot is against a black background.

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Exactly. The gun by my bed has been covered for years, guns that go outside remain uncovered. I'm not recommending this to anyone, it's just how it works for me. I have both eyes open all the time and focus on what I want to hit, it makes no difference to me covered or uncovered.
ETA: My comp M4s have the ARD screwed in which seems to help keep the brightness fairly constant and I'm used to shooting with those also.

Quote:

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Originally Posted by GTF425

I'm doing it because there were tenured members claiming that you'll be 12" plus off target at 25y if you use an occluded sight.
I am 100% confident that's not true, but am gathering the necessary target data to support the hypothesis.

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It's shooter dependent, and depends on the amount of phoria that person has. So, what your own results will only prove is what's true for you. In the old thread, what people were discussing was the POI change when you switch back and forth from occluding and looking through the same sight. If you zero occluded and use it that way, like an OEG, that will lessen the effect of a phoria if you have one. Note that phoria can change on the same person as the eye gets fatigued.

If you zero looking through the sight, then use it occluded, that's when you'll see a difference, if you have a phoria. If you don't, then you may not see the effect.
I think that a poll would be a good idea, with many people trying the SAME test, then chiming in with their results. Set up a rifle with red dot (this can be done at home) so that it's pointing out a window at a fixed point. Make sure it's in a rest or on a bipod and you don't move it. Look through the red dot, and confirm it's on the target. Flip the lens cover closed so you're using it occluded and see if the dot changes position on that target. If not, great. Your POI using the optic may be the same. If so, then you can see how much you'll be off.

For me, it's at least a foot at 25 yds difference in the dot shift. Note that I am left handed and shoot rifles using my left eye looking through sights or optics. However I am right eye dominant, so when I occlude the sight I'm now using my right eye to look at the target while the left eye sees the dot and superimposes it. So, this may also be a factor why I'm seeing such a big shift.
When I shoot pistol, I use my right eye (both eyes open). For me, the test is always the same - I see a significant difference in the position of the dot, every single time. YMMV.

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Originally Posted by militarymoron

In the old thread, what people were discussing was the POI change when you switch back and forth from occluding and looking through the same sight.

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I still can't wrap my head around that massive of a POI difference. I didn't have my Aimpoint out this weekend to even mess with this.

If this technique is a distraction for anyone for whatever reason I would advise against it. The small benefit is not worth any sacrifice in speed or accuracy. It's only useful if it provides you with an advantage.

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Originally Posted by markm

I still can't wrap my head around that massive of a POI difference. I didn't have my Aimpoint out this weekend to even mess with this.

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Well it's kind of like a person with good vision and no astigmatism wondering why someone with astigmatism is seeing a shooting star or snowman instead of a distinct red dot.
So, at 25 yds (75 ft), 1 foot equals less than one degree of angle. Look at a picture or clock on your wall about 7-8 feet away from you. Cross your eyes so you have two images (double vision). When I cross my eyes, the distance between the two images is about 4-5 feet depending on how hard I cross my eyes. That's about 30 degrees of eye misalignment.

Not everyone's eyes are aligned perfectly when one eye is occluded, so a small amount of drift/misalignment - less than a degree, can result in one foot at 25 yds. When both eyes are open, they compensate so you don't get double vision. However, as we get older, our eyes can fatigue more easily. Ever been really tired and had trouble focusing? When I was much younger, I couldn't understand why my dad had to take his glasses off to thread a needle. Now I have to do the same. I can't focus on the front sight of my handgun with my normal glasses anymore etc.

If you're don't experience it, you're fortunate, but need to understand that this is caused by differences in human vision, nothing to do with the optic or gun. If you can wrap your head around the different existing vision conditions that humans deal with on a daily basis, you can wrap your head around this :)

Added - Ok, I figured out a great experiment. Grab your rifle and turn on your red dot. Close the front lens cover, so you're using it occluded. Point it at any fixed object. Then cross your eyes. The dot will move a LOT from one side to another. Play around with some eye misalignments (crossing your eyes a little, a lot etc). See how much the dot moves? Then just think about how little it takes for the eyes to be misaligned to change the POI at distance. I hope that helps with understanding and visualizing it. Let me know how it goes.

50 meters, MP15-22, Eotech, 2” stick-on target, CCI Clean.
The setup:Attachment 71665

Results:Attachment 71666The 1s represent strong eye only, the 2s are for both eyes open, and the Os are for occluded. 5 shots ea.

Just did a rough non-firing experiment from the house with an aiming point of a gable end 50 yards across the street. Took aim with the cap closed and my support hand ready to flip it open. Every time I flipped the cap open the dot was actually like 16 inches right of where I wanted it.

I did same experiment. POI is expected 20moa to the right and 20moa low. Workable in short distance. Will help to place the reticle high left.

I probably won't use the technique. Cranking my lpvo down to 1x-2x will do better.

-TL

Sent from my SM-N960U using Tapatalk

Coincidentally I've been messing with this and getting similar results to what I'm seeing here.

Big relief. I thought my eyes were too far apart.

You guys are dot focused. If you are target focused youll be on target, thats why you have to do it quick and not stare through the scope.

If you stare at the target, pull the gun up and shoot quick, youll be much closer

The thing that I thought helped a decent amount was looking through the rear fixed iron app. Seemed to reduce the effect, but that method was ridiculously slow.

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Originally Posted by markm

Just did a rough non-firing experiment from the house with an aiming point of a gable end 50 yards across the street. Took aim with the cap closed and my support hand ready to flip it open. Every time I flipped the cap open the dot was actually like 16 inches right of where I wanted it.

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One of us, one of us. :p

You have to be target focused.

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Originally Posted by titsonritz

You have to be target focused.

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I'll have to look at it again. It's hard to say for sure because you're reconciling two different visions.

The easiest way to start is with a handgun, and tape over the dot. Stare at a target (dot on the wall, light switch, etc) and if your focus in either eye changes when you put the dot up, or if your eye moves to the dot, you need to train out of that.

Here's Ben Stoeger explaining it better than I can:
https://youtu.be/ZUnkfr6X3o4?si=kVYJubePGn93mcSo

Strikes me that it's reversing correct eye dominance into the left eye. No?

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Originally Posted by titsonritz

You have to be target focused.

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We're assuming people know how to use red dots. Being target focused doesn't fix phoria.

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Originally Posted by militarymoron

We're assuming people know how to use red dots. Being target focused doesn't fix phoria.

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The problem is people thinking they are target focused when they are not.


Occluding the dot is used to show you when you are and are not target focused. You physically cant be target focused and have phoria. Phoria by definition is divergence of focus.

Edit to clarify : when I say "focus" i mean eye convergence, both eyes focuswd on a singular object.

Edit 2: look at a stop sign, if you swipe your hand over an eye, does it need to refocus? No. An rds is different because attention is drawn to it.

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Originally Posted by MegademiC

Occluding the dot is used to show you when you are and are not target focused. You physically cant be target focused and have phoria. Phoria by definition is divergence of focus.

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You're bringing up two separate issues. One is the problem people have with where they focus their attention. It's referring to where their attention is going - are they staring at the target or tracking the dot. Ben explains it in the video.

A red dot is not like the front sight on a handgun. Focusing on the front sight makes the target blurry. With a red dot - whether the target is close or far, both the target and the dot remains in focus.

Phoria is another. You can totally be target focused and experience phoria. I guarantee that when I did my phoria experiments, my non-occluded eye was 100% focused on the target, which remained sharp. The dot just moved back and forth on the target when opening and closing the front cap. My attention and focus never moved from the target. Remember that when doing the experiment, the gun remains stationary on the target in a rest. The only moving thing is the front scope cover.
It's not like shooting a handgun that's recoiling and seeing whether you're looking at the target or tracking the dot instead.

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Originally Posted by militarymoron

You're bringing up two separate issues. One is the problem people have with where they focus their attention. It's referring to where their attention is going - are they staring at the target or tracking the dot. Ben explains it in the video.

A red dot is not like the front sight on a handgun. Focusing on the front sight makes the target blurry. With a red dot - whether the target is close or far, both the target and the dot remains in focus.

Phoria is another. You can totally be target focused and experience phoria. I guarantee that when I did my phoria experiments, my non-occluded eye was 100% focused on the target, which remained sharp. The dot just moved back and forth on the target when opening and closing the front cap. My attention and focus never moved from the target. Remember that when doing the experiment, the gun remains stationary on the target in a rest. The only moving thing is the front scope cover.
It's not like shooting a handgun that's recoiling and seeing whether you're looking at the target or tracking the dot instead.

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I know what you're talking about, one eye diverges from the target.
How fast did the dot move when you closed the cap? IME, it can be trained a bit. Also, the less time behind the occluded dot, the less divergence. If you get behind the dot and shoot in 1 sec, how far off are you? How about 0.5s?

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Originally Posted by MegademiC

I know what you're talking about, one eye diverges from the target.
How fast did the dot move when you closed the cap? IME, it can be trained a bit. Also, the less time behind the occluded dot, the less divergence. If you get behind the dot and shoot in 1 sec, how far off are you? How about 0.5s?

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It was years ago when I shot and experienced it - both slow fire and snap shots with my AR. I first noticed it off the bench, then experimented during drills with snap shots. Doing the experiment recently with fixed rifle aimed at a fixed target, the dot shift is immediate the moment I close the cap. It jumps instantly when I switch from sighting through the optic to occluding it. Again, this is dependent on the individual's eyes; just like eyesight/prescription. Some have it worse than others. If you don't, that's great.

Have you tried shooting slowly instead of fast to quantify the shift (if any) due to phoria? Try shooting 25yd groups slow fire to compare non-occluded and occluded to get your true offset due to phoria. That's just to identify and quantify the offset if any. Then you can work on reducing the effect if you have to. What happens when you experiment at home with a fixed rifle on a fixed distant target. Any dot movement when you switch from open to occluded?

GTF425 is a professional nerd on the human body and abnormalities thereof, and some of what y’all are debating is exactly why he trains with occluded dots. He also trains with professional shooters and likely tests these ideas on them. Plus the infantry NCO experience, which is where I picked it up as a technique to force dudes (and myself) to be more target-focused in CQB. Y’know, dudes that thought they were, but weren’t.

There’s a good reason why when he suggested that I test the shift past shoothouse distances, I immediately did, and it wasn’t just morbid curiosity. I have no doubt that some of you may have anatomical, physiological, or neuropsychological reasons this won’t work for you, but you’re almost certainly in a single-digit minority. I mean, my left eye doesn’t even work right due to a cranial nerve injury, which makes it very difficult to practice this technique with a rifle and causes me all sorts of headscratcher problems, yet I was able to demonstrate a very small shift when occluded.

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Originally Posted by 1168

GTF425 is a professional nerd on the human body and abnormalities thereof, and some of what y’all are debating is exactly why he trains with occluded dots.

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Are you saying it is possible to train away phoria? There are exercises like the Brock String to improve convergence but it is not clear if these can correct an underlying muscular imbalance or simply improve the use of musculature when both eyes are working together, and I wonder it helps only around the arms length distance that the String is used and not convergence at 25 yards etc.

My phoria doesn't seem to have much effect on snap shooting with a micro red dot mounted forward, but slow shooting with a scope that takes up a larger part of the eye's field of view seems unpredictable.

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Originally Posted by GTF425

I'm planning to also test this with a 4x ACOG, 1-6x Razor at 1x/3x/6x, and to stretch the RDS' legs to see how far it can effectively be used while covered.

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I await the results of this.

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Originally Posted by MegademiC

You guys are dot focused. If you are target focused youll be on target, thats why you have to do it quick and not stare through the scope.

If you stare at the target, pull the gun up and shoot quick, youll be much closer

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This has been my experience. You're looking over the optic, bring the dot up to the target and shoot. If I'm gonna be looking through the optic for any length of time I'd rather have the front cap open.