Be aware, possible visual occlusion open emitter optics.

[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]

Attachment 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.



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.

[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



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



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)

[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.