So, yeah... I'm at a loss. There's no reticle or screen information to get sharp and in focus so 1)Does it matter? and 2) If it does matter whats the process?
Thanks guys!
-From a nOOb on toobs
Thanks guys!
-From a nOOb on toobs
Night Vision How do you set the diopter on a PVS-14?
- Thread starter nikonNUT
- Start date
It’s more like setting a focus. Focus the objective on something as good as you can get it, then mess with the eyepiece adjustment to see if you can make it better or worse. At least that’s what I do. When you mess with the eyepiece, you can easily see the changes.
Thank you guys! I ended up holed up in my room and focused on a box 10-ish feet away. Got the image as not sucky as possible and then played with the diopter until I could see the individual lines on the barcode. Still sucked so I put my readers on and repeated. Got a much better image so the PVS-14 is set and I need +2.5 diopter shooting glasses... Damn it! I think my next big purchase is going to be Ortho-K lenses. Kinda like braces for eyes. Sleep in them and the lens contour corrects near vision.
So one more question... I would really rather wear my 0.0 dipoter shooting glasses than my reading glasses when under the NODs (BTW I can focus my MH25 for a clear screen no problem) so I was admiring my PVS-14 and it looks there is a lock ring for the occular lens to jam against. Is that adjustable? If so is there 1) Any set screws I should be aware of? 2) A torque spec for re-tightening post adjustment and 3) Will adjusting it cause all the nitrogen to be lost requiring having the unit purged again? I would like to have a "0.0 diopter" for me and that would still leave -6.0 to +2.0 for anyone I wanted to loan it to that isn't blind! Just thinking out loud and I really don't wanna break it. Thank you again for the information all and for putting up with my dumb ass questions!
I always teach it as "make the static sharp." If it looks pretty good, focus it more badly or look at something at the wrong distance. Use the day cap to make it darker to get scintillation.
Same as always for diopter adjustment on riflescopes: do it fast, then look away for a moment. Your eyes will try to adjust and over time it'll add strain.
Then, focus the objective to distance. Tweak if needed and as you go along.
I never purge. Anything. Taken apart plenty of optics, electro-optics. It get lost over time anyway, only real reason to do it is if diving or similar to keep positive pressure, and then right before you need it.
The ring on the occular lens is a jam nut to keep the occular lens assembly from unscrewing. It's not an adjustment ring in the way the objective has one. If not hard against the housing, fix that
I have gone to entirely wearing progressive lenses, because I am old. With those I can look through the distant part for the optics, but then can look down to see compasses, bits of paper, and especially the "ATAC" mounted to my chest. But, with the adjustment anything will do, wear what you like. Seen lots of choices work.
I WILL encourage something even if you do not need correction. Shooting, dust from vehicles and helos, etc aside, dark and limited DOF make it easy to walk into sticks, so I encourage eyepro with NODs. If you think they protect you (they don't) then what about when you flip or pod up? Yeah, you want eyepro on all the time.
Same as always for diopter adjustment on riflescopes: do it fast, then look away for a moment. Your eyes will try to adjust and over time it'll add strain.
Then, focus the objective to distance. Tweak if needed and as you go along.
I never purge. Anything. Taken apart plenty of optics, electro-optics. It get lost over time anyway, only real reason to do it is if diving or similar to keep positive pressure, and then right before you need it.
The ring on the occular lens is a jam nut to keep the occular lens assembly from unscrewing. It's not an adjustment ring in the way the objective has one. If not hard against the housing, fix that
I have gone to entirely wearing progressive lenses, because I am old. With those I can look through the distant part for the optics, but then can look down to see compasses, bits of paper, and especially the "ATAC" mounted to my chest. But, with the adjustment anything will do, wear what you like. Seen lots of choices work.
I WILL encourage something even if you do not need correction. Shooting, dust from vehicles and helos, etc aside, dark and limited DOF make it easy to walk into sticks, so I encourage eyepro with NODs. If you think they protect you (they don't) then what about when you flip or pod up? Yeah, you want eyepro on all the time.
Gotcha! Eye pro good but I knew that (lots of things here that will poke an eye out in dark!). Occular lens position fixed and non-adjustable. Check! And it is all the way down! Here's where I am not tracking. "Make the static sharp" I don't quite follow. Can you please expound? What I think I am hearing put on the day cap, get the object focus "off" aka blurry-ish, turn the gain all the way up, and make sure the little sparklies are sharp pin pricks of light and not little blobs (for lack of a better word) while taking breaks from screen time so to speak? Does that sound close? As for purging... I know nothing of the process/advantages but in my AO a good night is 87% humidity. A bad night? Well, it's a good thing the PVS-14 is submersible to 66 feet!I always teach it as "make the static sharp." If it looks pretty good, focus it more badly or look at something at the wrong distance. Use the day cap to make it darker to get scintillation.
Same as always for diopter adjustment on riflescopes: do it fast, then look away for a moment. Your eyes will try to adjust and over time it'll add strain.
Then, focus the objective to distance. Tweak if needed and as you go along.
I never purge. Anything. Taken apart plenty of optics, electro-optics. It get lost over time anyway, only real reason to do it is if diving or similar to keep positive pressure, and then right before you need it.
The ring on the occular lens is a jam nut to keep the occular lens assembly from unscrewing. It's not an adjustment ring in the way the objective has one. If not hard against the housing, fix that
I have gone to entirely wearing progressive lenses, because I am old. With those I can look through the distant part for the optics, but then can look down to see compasses, bits of paper, and especially the "ATAC" mounted to my chest. But, with the adjustment anything will do, wear what you like. Seen lots of choices work.
I WILL encourage something even if you do not need correction. Shooting, dust from vehicles and helos, etc aside, dark and limited DOF make it easy to walk into sticks, so I encourage eyepro with NODs. If you think they protect you (they don't) then what about when you flip or pod up? Yeah, you want eyepro on all the time.
You got it. The random sparkles are called scintillations, but overall the image in the dark will be grainy, even for the highest resolution tubes, so easy to see individual dots at least when they are at reasonably high contrast.
Usually the term "static" works great, half a dozen people standing there slowly adjusting the position then I say this and they go "ah," then when objective focus "oooh..."
Purge puts a clean, dry gas under slight positive pressure to keep from internal condensation, dust, etc and to avoid external atmosphere intrusion.As for purging... I know nothing of the process/advantages but in my AO a good night is 87% humidity. A bad night? Well, it's a good thing the PVS-14 is submersible to 66 feet!
However, look at all the seals on the device here, how some are not really truly optimal seals (the lenses threading in and out) and you can guess what is true: the purge will within a matter of months (esp when used regularly) simply go away. Once reduced to 1 atmosphere, external air can get in. So the military has purge units and re-does it every once in a while. Not sure the schedule.
Nitrogen is the standard but that's not magic, it's just air without O2, water, and... that's it. N2 used for purging is not lab grade so has the normal trace elements of the air in it, is mostly just a convenient source of clean-and-dry.
I am very very very not alone in being one who says just use good practice when building/repairing, to keep things dust free (and when not in a cleanroom, "good practice" includes tricks like leaving open parts upside down as dust mostly falls) and use the miracle of modern civilization of air conditioning, do it when the room air is dry-ish and you'l be fine. People repair cameras, lenses, and many devices with no purge, and no problems. Many other devices (say, Nikon lenses) are factory filled with 1 ATM N2; they make most camera lenses in a box filled with nitrogen but do not have a purge valve to pressurize it, for example.
I live in Kansas City, and bop mostly around this area where it gets to condensing humidity sometimes, esp morning in a hollow in the woods.
IF you worry about it, or see consequences like internal condensation, then my suggestion is not to go source a USGI purge kit or make something, but get a wine preserver like this. Argon is an excellent purge gas (and some optics do use it at the factory), is utterly inert so better in theory for corrosion etc but for our purposes the best bit is that it is notably heavier than air. So, you open the purge screw, face it upward, squirt in a reasonable amount of Ar, put the can down and at your leisure put the purge screw back on. Because it cannot leak out easily, but sits there much like you just filled it with water.
(The wine kits are not just convenient and cheap but low pressure! Do not try to put argon shield gas in, as it's WAY too high pressure so might damage the inside, and will splash out. If clever enough to mess with gasses you need to regulate to like 4 psi and have a flow rate at or under 1 CFM).
All adjusted guys! Thank you very much! I tried setting diopter 3 different ways...
1) Holed up in my room and did the previously mentioned focus on the barcode on a box method
2) Used the method suggested by @shoobe01
3) Went and found a really dark spot, set the occular to infinity (sort of. More on this in a second) and adjusted until sharp!
Lo and behold I discovered that the diopter landed in exactly the same spot (or as close as I can discern) with all three methods! I also discoved that I an fricken' blind!!! Like +2.5 shooting glasses PLUS +1.0 on the occular blind!!! All good!
OK, Last qustion since we are on the topic. I noticed that when star gazing I could adjust to infinity (stars are nice and sharp and still had some adjustment left and could get them to go out of focus again. Should I adjust the infinty stop or just roll with it? I'm good either way but the allen wrench required to undo the grub screw is a 0.035" aka 0.9MM correct? Thank you again. Y'all ROCK!
1) Holed up in my room and did the previously mentioned focus on the barcode on a box method
2) Used the method suggested by @shoobe01
3) Went and found a really dark spot, set the occular to infinity (sort of. More on this in a second) and adjusted until sharp!
Lo and behold I discovered that the diopter landed in exactly the same spot (or as close as I can discern) with all three methods! I also discoved that I an fricken' blind!!! Like +2.5 shooting glasses PLUS +1.0 on the occular blind!!! All good!
OK, Last qustion since we are on the topic. I noticed that when star gazing I could adjust to infinity (stars are nice and sharp and still had some adjustment left and could get them to go out of focus again. Should I adjust the infinty stop or just roll with it? I'm good either way but the allen wrench required to undo the grub screw is a 0.035" aka 0.9MM correct? Thank you again. Y'all ROCK!
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Your choice.
Officially, tweak the infinity stop to perfectly align.
Me, I have had a couple of the stops loosen or crack or so on in the field (once because riding in a truck on rough roads a long time I think) and always slipping till stuck at short focus so I couldn't get it to infinity without light and small tools. The little extra I have dialed into all mine now but it's "wrong."
Officially, tweak the infinity stop to perfectly align.
Me, I have had a couple of the stops loosen or crack or so on in the field (once because riding in a truck on rough roads a long time I think) and always slipping till stuck at short focus so I couldn't get it to infinity without light and small tools. The little extra I have dialed into all mine now but it's "wrong."
Good info! Been a machinist for a long time and I am kind of wary of plastic threads and metal set screws to be honest. I'm sure that little grub screw has dug into the plastic and raised a burr that could cause fits! I can't tell you how many times I have had to machine pistons off rams (Hydraulic cylinders) because a customer or manufacturer ran a set screw into threads without a nylon puck or ball as a buffer. We remove the set screw, turn the piston, and the threads seize instantly! I think I'll not mess with it. It's not life or death if I over shoot infinity.
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