Be aware, possible visual occlusion open emitter optics.

[Cdub_NW]

First time I have experienced this failure and would not have believed it if I hadn't seen it. (also captured on video)

Conditions: mid 40's, raining, heavy cloud cover. While down at PFC in Vegas earlier this week I was doing some structure clearing training. One of the dudes on the team runs a G17, RMR type2. After moving into position prior to punching out to engage a reasonably far target from behind a barricade he purposefully exhaled his breath, pistol was in a compressed high ready.

As he punched out after his intentional breath, he couldn't find the dot. He pulled back behind cover after realizing the dot was being impacted by the system being fogged from his breath. Took about 12 seconds for the system to clear and dot to become useful again. We stopped the series to dig into the failure. The objective lens was obviously obscured but the failure was the emitter itself. We handed him my pistol with an RCR to perform the same test, rear lens was fogged just the same but dot was not completely obscured. Performed the same set of circumstances with my second rig running 509T2 with the same result.

This was a perfect storm of technique, conditions, equipment but a result is a result regardless. This could obviously be trained out of him BUT it highlights a shortcoming of an open emitter system in this condition set.

Something to test yourself but figured this info could be lifesaving for some of you.

To that note, everyone on the team is moving to an enclosed emitter optic immediately.

[Ndbbm]

Just curious, were the iron sights still usable? Also how’s the conceal ability on the RCR? I find the acros to not really be where I want them and am currently using a holosun Glock scs. Which as an aside during my rds transition course (3 days which was relatively warm but rainy/drizzly) I didn’t have any issues with the scs but we had 4 acros fog so bad the dot and irons were not visible ( I believe aimpoint replaced all four under warranty)

Jason

[Utm]

Just curious, does this officer ever treat his optic with any anti fog?

[Tokarev]

my pistol with an RCR...

Where did you get the RCR? I've had one on order since the initial launch and am still waiting.

Sent from my SM-S901U using Tapatalk

[Cdub_NW]

Where did you get the RCR? I've had one on order since the initial launch and am still waiting.

Sent from my SM-S901U using Tapatalk

Walked into my local amazing FFL Deschutes Arms & Munitions and he had two on the shelf. Right place right time. But I love it. This shop also had a ton of the Garmin chronograph units early on. Solid shop for sure!

[Basher]

Just curious, were the iron sights still usable? Also how’s the conceal ability on the RCR? I find the acros to not really be where I want them and am currently using a holosun Glock scs. Which as an aside during my rds transition course (3 days which was relatively warm but rainy/drizzly) I didn’t have any issues with the scs but we had 4 acros fog so bad the dot and irons were not visible ( I believe aimpoint replaced all four under warranty)

Jason

Any idea of where those ACROs fell in the serial number range? Just curious as I'll be in the market for one soonish and if they're older models I'll make sure to steer clear of the earlier serials. If they're newer, I guess I'll just have to roll the dice and test mine out myself when I get it...

[Cdub_NW]

Just curious, were the iron sights still usable? Also how’s the conceal ability on the RCR? I find the acros to not really be where I want them and am currently using a holosun Glock scs. Which as an aside during my rds transition course (3 days which was relatively warm but rainy/drizzly) I didn’t have any issues with the scs but we had 4 acros fog so bad the dot and irons were not visible ( I believe aimpoint replaced all four under warranty)

Jason

Irons were not initially visible in the lighting conditions but became visible quicker than the emitter to unfog in the ambient air on his RMR.

Concealability is fine with the RCR as you'd expect. Larger footprint than irons of course but nothing that impacts what I wear clothing wise. Fits all my holsters the RMR was in: JMCK AIWB, Safariland DSO, T-Rex.

[Cdub_NW]

Just curious, does this officer ever treat his optic with any anti fog?

Yes the objective lens, but not the emitter. We re-applied immediately and did have shorter dwell time for fog to clear after on the objective lens but the emitter fogging was still an issue on the RMR.

I noticed some rain drops on my rear lens but nothing that hindered acquiring the dot.

One guy in the training had an SRO that turned into a kiddy pool in the rain we were in. Could not get his optic clear, ended up missing the first shot (cleared during recoil) but cost him time. He is also ditching the SRO (thankfully)

[Ndbbm]

Any idea of where those ACROs fell in the serial number range? Just curious as I'll be in the market for one soonish and if they're older models I'll make sure to steer clear of the earlier serials. If they're newer, I guess I'll just have to roll the dice and test mine out myself when I get it...

No idea, I believe all came from the same seller same batch. One of the ones that didn’t fail I. The class later was replace under warranty when the control panel failed. I believe they were all P2s though. I haven’t heard of any issues with the replacements.

Jason

[Clusterfrack]

I just got back from a local USPSA match, with biblical rain. On the 4th target of a stage the rain was so heavy that water covered the emitter and the dot was projected in the wrong direction. It cost me quite a bit of time, and points. I really wish there was a large window closed emitter optic.

[TCinVA]

As he punched out after his intentional breath, he couldn't find the dot. He pulled back behind cover after realizing the dot was being impacted by the system being fogged from his breath.


I've seen this several times.

It's one of the reasons why I prefer an enclosed emitter optic. Even with the lenses fogged, the projection of the dot isn't impacted so you can still usually see a dot. When the emitter is open to the elements and the glass is open to the elements it's a lot easier for the projection of the dot to be interfered with.

I've mentioned this a few times elsewhere, only to experience hand waving and bullshit. It's not something you should stay up at night worrying over, but you should know it's a thing and take preventative measures understanding that even with as much prevention as you can do, it's still a thing you can run into.

[TCB]

Until you put in work in extremely challenging environmental conditions you don’t truly understand the limits of your gear.

[mmc45414]

Until you put in work in extremely challenging environmental conditions you don’t truly understand the limits of your gear.

I was at a three gun match once when it started raining buckets right before my turn, and the reticle on the EOtech was just fine, but you couldn't see a damn thing through it, for sure not unpainted steel plates at ~90yds. Ever since that day I have been meaning to mount offset peep sights, for gaming and potential zombies.

[Basher]

Until you put in work in extremely challenging environmental conditions you don’t truly understand the limits of your gear.

And this is just another reason I give for why competitions are beneficial. Not only do they validate training, but they can validate gear selection as well. Most of us choose to hit the range on calm, sunny days when we'll be nice an comfy (and I'm 110% guilty of this myself), but competitions offer at least some rigidity in the environment and conditions present (with some exceptions). I always tell people to shoot a few outside matches a year for this reason. :)

[Clusterfrack]

I just got back from a local USPSA match, with biblical rain. On the 4th target of a stage the rain was so heavy that water covered the emitter and the dot was projected in the wrong direction. It cost me quite a bit of time, and points. I really wish there was a large window closed emitter optic.


https://youtu.be/z5qPGHT40T0
15A2C1D HF5.0

[GJM]

https://youtu.be/z5qPGHT40T0

I would be curious how a 507 Comp in circle mode would have worked in this scenario?

[Clusterfrack]

I would be curious how a 507 Comp in circle mode would have worked in this scenario?

That's a really good question. Water flooded the housing around the emitter, causing the dot to appear very high in the window. It was not visible with a proper index. I'm guessing that the circle would have been affected similarly by the lens created by the water. But it might have been more obvious what was going on.

[TCinVA]

https://youtu.be/z5qPGHT40T0

Things I've heard that your video nicely disproves:

- Bro, just shoot the gun and the water will clear out!
- It's a concealed carry gun, it's not like water is going to get in the emitter! (The fact that the gun is actually out of the holster when you need it seems to be lost on some folks)

[zcap]

Until you put in work in extremely challenging environmental conditions you don’t truly understand the limits of your gear.

100% this. Here are some things I learned from testing pistol RDS in water, rain, humidity, extreme temperature transitions, and sub zero cold.

1. Not all open emitters are equal. Some, eg the DPP, are extremely susceptible to minimal amounts of debris or water interfering with dot projection.

2. Spray on anti-foggers are generally not very effective as they leave only a very thin hydrophobic film. You can apply multiple coats to increase effectiveness, but paste is much more effective as you can quickly apply a thick layer and then thin it out until the dot is relatively sharp and you can see through the glass. A bright high quality emitter allows running with a thick hydrophobic layer and this has largely eliminated fogging under conditions that I have tested.

3. LPVOs and enclosed dots can also fog. Internal seals can be compromised after extended use, or even limited exposure to extreme temperatures. Once a seal is compromised these units can fog internally and occlude your irons with no quick remedy. Regardless of the tech, you need a backup sighting technique.

4. Enclosed pistol red dots often weigh upwards of 2x open emitter dots and that additional weight narrows the slides cycling window. Under standard range conditions this may not be noticeable, but combine that extra weight with another factor like below freezing temperatures and suddenly cycling issues can manifest. In other words, running a heavier enclosed red dot may require a lighter recoil spring to maintain the slide's cycling window.

[TCinVA]

114497

Couple of years ago, out handling one of the occasional blizzards we get and checking in on some people who had the misfortune of a pretty bad case of COVID right as they were snowed in. I did some shoveling and running the snowthrower, so I was jacketless. Ended up sliding down their hill head first, pistol and holster ended up like a bucket collecting ice. Thought I'd have to shoot their methhead neighbor's rotweiller.

Glass was fogged to the point where I couldn't see sights. But I could make out the dot through the fogged rear lens. It was pretty much just a fuzzy occluded optic at that point. I've since shot in a fair bit of cold weather with the gun and verified I can absolutely shoot accurately with the rear lens fogged.

It's not a thing until it's a thing. It seems like much more of a thing once it's happened to you.

[GJM]

100% this. Here are some things I learned from testing pistol RDS in water, rain, humidity, extreme temperature transitions, and sub zero cold.

1. Not all open emitters are equal. Some, eg the DPP, are extremely susceptible to minimal amounts of debris or water interfering with dot projection.

2. Spray on anti-foggers are generally not very effective as they leave only a very thin hydrophobic film. You can apply multiple coats to increase effectiveness, but paste is much more effective as you can quickly apply a thick layer and then thin it out until the dot is relatively sharp and you can see through the glass. A bright high quality emitter allows running with a thick hydrophobic layer and this has largely eliminated fogging under conditions that I have tested.

3. LPVOs and enclosed dots can also fog. Internal seals can be compromised after extended use, or even limited exposure to extreme temperatures. Once a seal is compromised these units can fog internally and occlude your irons with no quick remedy. Regardless of the tech, you need a backup sighting technique.

4. Enclosed pistol red dots often weigh upwards of 2x open emitter dots and that additional weight narrows the slides cycling window. Under standard range conditions this may not be noticeable, but combine that extra weight with another factor like below freezing temperatures and suddenly cycling issues can manifest. In other words, running a heavier enclosed red dot may require a lighter recoil spring to maintain the slide's cycling window.

For all these reasons, I think the EPS full size and carry are the ideal defensive optics. They are sealed, lightweight, give you a choice of 2 or 6 moa dots, and have a low enough deck height that normal height sights usually work.

[Navin Johnson]

114497

Couple of years ago, out handling one of the occasional blizzards we get and checking in on some people who had the misfortune of a pretty bad case of COVID right as they were snowed in. I did some shoveling and running the snowthrower, so I was jacketless. Ended up sliding down their hill head first, pistol and holster ended up like a bucket collecting ice. Thought I'd have to shoot their methhead neighbor's rotweiller.

Glass was fogged to the point where I couldn't see sights. But I could make out the dot through the fogged rear lens. It was pretty much just a fuzzy occluded optic at that point. I've since shot in a fair bit of cold weather with the gun and verified I can absolutely shoot accurately with the rear lens fogged.

It's not a thing until it's a thing. It seems like much more of a thing once it's happened to you.

BAC might be worth practicing for such an occasion.

[TCinVA]

It works just fine. It was no different, really, than shooting with a paster over my optic as I demonstrate in class.

It's not difficult unless it's the rear lens that is blocked by something you can't wipe away. Then you're down coping techniques that are pretty unreliable past about 5 yards.

[zcap]

Things I've heard that your video nicely disproves:

- Bro, just shoot the gun and the water will clear out!
- It's a concealed carry gun, it's not like water is going to get in the emitter! (The fact that the gun is actually out of the holster when you need it seems to be lost on some folks)

In my testing, while not as bad as the DPP, the SRO is highly susceptible to dot dispersion from light rain, even after hydrophobic lens treatment. On the other hand, I can go for a swim with an RMR with the same hydrophobic lens treatment and the dot is immediately visible for acquisition as soon I draw my pistol. Both dots being from the same manufacturer, I was tempted to make generalizations about performance, but real world testing and experience destroys my hypotheses time after time. After extensive testing, I have zero issues carrying an RMR with lens treatment, even when working in areas with some of the highest annual precipitation levels in the US.

[Cdub_NW]

Things I've heard that your video nicely disproves:

- Bro, just shoot the gun and the water will clear out!
- It's a concealed carry gun, it's not like water is going to get in the emitter! (The fact that the gun is actually out of the holster when you need it seems to be lost on some folks)

^^ THIS! I have heard the same things as well. In fact, our head instructor crapped all over those statements. Not to mention in a fight you likely don't have the luxury to simply burn a round into the berm to clear out the optic. Burning a round in a fight could get you killed, someone else killed or generally cost you time/rounds, all are bad options.

After this last event, I am firmly in the closed emitter camp and this further confirms my findings under use in all conditions.

[GJM]

I did some testing with a 507 Comp this morning. Since I had a bottle of lens cleaner handy, I thoroughly doused the emitter on a 507 Comp, with the 2 moa dot selected. Note, this wasn't a drip or two of liquid, but rather I doused it. This is what it looked like -- a thoroughly unusable dot.

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First, I switched to the 8 moa circle, and it still wasn't satisfactory. When I switched to circle only, even though the splatter was still there, the circle would have worked. The picture wasn't a good representation of what I saw, but you get the idea. For the same reason a circle works with a low sun angle, it seems like an option when moisture could get on your emitter.

114585

[zcap]

I did some testing with a 507 Comp this morning. Since I had a bottle of lens cleaner handy, I thoroughly doused the emitter on a 507 Comp, with the 2 moa dot selected. Note, this wasn't a drip or two of liquid, but rather I doused it. This is what it looked like -- a thoroughly unusable dot.

First, I switched to the 8 moa circle, and it still wasn't satisfactory. When I switched to circle only, even though the splatter was still there, the circle would have worked. The picture wasn't a good representation of what I saw, but you get the idea. For the same reason a circle works with a low sun angle, it seems like an option when moisture could get on your emitter.



Thanks for posting. Actually testing gear leads to insight.

Here are some pics with an RMR with a hydrophobic wax lens treatment.

1. RMR with lens treatment and drain holes taped and filled to overflow with water

114592

2. RMR with lens treatment sight picture while filled with water.

114593

3. RMR with lens treatment sight picture after draining (happens nearly instantaneously if drain holes are not taped, ie within the timeframe of a holster draw)

114594

[YVK]

What brand lens treatment are folks using?

[Clusterfrack]

Good post zcap. My most recent problem (see above) was from a drop of water covering the emitter, not the lens. Recoil didn’t work to clear it. I wonder if a hydrophobic coating would help.

[GJM]

Good post zcap. My most recent problem (see above) was from a drop of water covering the emitter, not the lens. Recoil didn’t work to clear it. I wonder if a hydrophobic coating would help.

This was my question, are we trying to protect the lens or the emitter?

I once fell in a snow pile with a RMR, and a bit of snow on the emitter caused a massive starburst.

[zcap]

Good post zcap. My most recent problem (see above) was from a drop of water covering the emitter, not the lens. Recoil didn’t work to clear it. I wonder if a hydrophobic coating would help.

To clarify, I also coat the emitter lens with wax treatment as well. In addition to filling the main body with water, I submerged the lenses in water as well, but most of the water immediately runs off when I level the pistol due to the coating.

Here is the same test with an SRO. As I mentioned earlier in the thread, the SRO performance in water does not match the RMR. This is sort an extreme test since I use tape to purposely prevent drainage and fill the SRO to the max possible level, but under these extreme conditions the SRO dot is not usable. However, as soon some of the water drains the dot returns with usable clarity.


1. SRO with lens treatment, drain holes taped, filled to overflow with water.

114596

2. Sight picture of SRO with lens treatment, drain holes taped, filled with water. The dot SHOULD BE right above the front sight, but instead a faint ghost dot appears much higher in the window.

114597

3. Sight picture of SRO with lens treatment after most of the water draining (should happen quickly if the drain holes aren't taped). The dot is now in the correct position, and has minimal dot dispersion.

114598

[zcap]

What brand lens treatment are folks using?

In my experience most wax or paste products work well, but liquid products don't leave enough hydrophobic film to be effective. EK Products makes a wax product (https://www.bigtexordnance.com/product/big-tex-ordnance-cat-crap-lens-cleaner-paste-retro-logo/) that works well and is widely available. However, as I have posted, some open emitter dots are much more susceptible to water than others, so you'll want to test your chosen dot with whatever coating you choose.

[Erick Gelhaus]

Interesting. Have seen enough issues with openly carried, open emitters, though this is a new one. I'll keep an eye out the rest of winter & into spring.

It does that winter has been paused, at the least, in my area. Sad, i was looking forward to trying to stuff out.

[zcap]

Related to the OP, here is how a hydrophobic wax treatment affects fogging on both open and enclosed emitter optics:

RMR completely untreated (left) and RMR with wax treatment on emitter window and both sides of lense (right), 57 degree fahrenheit ambient temperature

114607

RMR completely untreated (left) and RMR with wax treatment on emitter window and both sides of lense (right), immediately after breathing on both units (untreated unit dot completely disappears)

114608


enclosed emitter, untreated lenses, 57 degree fahrenheit ambient temperature

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enclosed emitter, untreated lenses, immediately after breathing on lenses (dot is fainter but still visible, sight becomes occluded)

114610

closed emitter, both lenses treated, immediately after breathing on lenses (dot maintains brightness, sight is mostly unclouded)

114611