Archived Posts » 59,672,804
Is there any truth to this?
3/4/2012 1:13:01 AM
- Anonymous Retailer
"A blemish is an obvious mark on the image
~.003mm to .015.
Anything smaller is disregarded industry wide"
Also, I'm not trying to start any arguments here as I'm seeing an increased amount of aggression over one's personal knowledge. My other question is that the typical PVS-14 weapon mount isn't truly regarded as weapon safe due to the fact that the housing threads are plastic or helicoils glued to the plastic. What about the other weapon mount platforms? Could damage occur if a mount could theoretically mitigate felt recoil to the optic itself (I.E. the LaRue STOMP)?
"A blemish is an obvious mark on the image
~.003mm to .015.
Anything smaller is disregarded industry wide"
Also, I'm not trying to start any arguments here as I'm seeing an increased amount of aggression over one's personal knowledge. My other question is that the typical PVS-14 weapon mount isn't truly regarded as weapon safe due to the fact that the housing threads are plastic or helicoils glued to the plastic. What about the other weapon mount platforms? Could damage occur if a mount could theoretically mitigate felt recoil to the optic itself (I.E. the LaRue STOMP)?
3/4/2012 9:02:12 AM
Originally Posted By 11bravo01:
- Anonymous Retailer
"A blemish is an obvious mark on the image
~.003mm to .015.
Anything smaller is disregarded industry wide"
Also, I'm not trying to start any arguments here as I'm seeing an increased amount of aggression over one's personal knowledge. My other question is that the typical PVS-14 weapon mount isn't truly regarded as weapon safe due to the fact that the housing threads are plastic or helicoils glued to the plastic. What about the other weapon mount platforms? Could damage occur if a mount could theoretically mitigate felt recoil to the optic itself (I.E. the LaRue STOMP)?
- Anonymous Retailer
"A blemish is an obvious mark on the image
~.003mm to .015.
Anything smaller is disregarded industry wide"
Also, I'm not trying to start any arguments here as I'm seeing an increased amount of aggression over one's personal knowledge. My other question is that the typical PVS-14 weapon mount isn't truly regarded as weapon safe due to the fact that the housing threads are plastic or helicoils glued to the plastic. What about the other weapon mount platforms? Could damage occur if a mount could theoretically mitigate felt recoil to the optic itself (I.E. the LaRue STOMP)?
A lively discussion isn't quite an argument and all parties usually agree on technical matters - unless the actual technical matter is either unknown or undetermined.
Anyway, blemish is not the correct term, just a generally used one. There's chicken wire and dark spots. Take your pick. :) It could be bright spots too, but that's another matter.
For chicken wire, any length of less than 0.003 inches ( not 0.003 mm, which is finer than the fibers of the plate and would be invisible ) are to be disregarded. For an understanding of how big that is, 0.003" is about 0.08mm, which is about 1/10th the diameter of a normal halo... So we're talking about blemishes that are very small, but big enough to notice easily.
For dark spots, any of diameter smaller than 0.003 inches are simply not recorded, however two dark spots of such size, close together so that the gap between them is smaller than the size of the spot, will be added together, eg, 0.003" dark spot plus 0.002" space plus 0.002" space is to be considered as a 0.007" blemish and counts against the tube, while either by itself would not.
This isn't something the industry decide - it's a matter of the milspec - and the above is current ( Omni VIII )
As for the PVS-14, there are two matters. The first is that the PVS-14 isn't designed for anything more than 5.56 - including the housing. That's a matter of public record and is recorded in the patent. And it goes for every part of the housing - threads, mounts, flanges... You name it.
The other matter is that some of them actually do break under higher levels of recoil.
Now the problem some of us have with anyone who claims to have a magic recoil-proof tube or housing ( lately using such oxymorons or perhaps tortologies as "Beyond Milspec" which seems to me to mean "Does not meet Milspec" since a device is either milspec or not! ) is that often the only testing done on such devices is recoil testing on a rifle - which is OK, but since they do not re-engineer the PVS-14 or determine if it can handle the recoil - tube or housing - then it's really not right to make the claim. Further, such testing is limited and does not reasonably preclude failure under tactical circumstances. For the safety of those who actually use NV in life or death situations, the only conscientious choice is to respect the manufacturers ratings and not to misrepresent the product.
That's not to say that it's impossible to make a special mount to mitigate recoil, because they do exist, but it's more just about being responsible and honest in the claims made. If a certified engineer wants to put his name to a product and claim that the product is designed for such purposes, then that's reasonable. Anything short of that, IMO, is not.
Put simply, those of us who have some level of experience in the matter like to see claims backed up by science and engineering. Not by marketing hype. And our primary motivation is the safety of people who use the equipment.
Even then, you'll find most of us support the experimenters out there. People who try to go against the grain and make a recoil-proof housing or mount. It's great that that happens. Just be open and honest about any claims you may make :)
Anyway, I hope that helps put things in perspective. :)
Feel free to question, criticise or comment on the above - :) I don't mind discussion and don't consider it to be an argument - because ultimately we all gain from accurate information... You'll find there are plenty of experts on this forum who will correct me when I'm wrong... Which happens more often than I like to admit :)
Regards
David
3/4/2012 2:22:36 PM
That's fantastic information and anything I've ever learned has been through sites like these. I recently bought a set of 14's and I have a little bit of everything you mentioned, including a bright spot that you didn't go in to detail about. What does the 'chicken wire' determine about the tube? I've been to the range a few times with it and aside from blacking in and out, everything functions fine. I'm running on a Wilcox mount and DBAL when I use my ACH and a GG&G aimpoint twist base when I'm running it on my AR. I don't plan on using anything greater that 5.56 because as you and others have mentioned; there is no conclusive evidence that such mounts mitigate recoil to the optic as sensitive as night vision. I appreciate the information and sometimes better research outweighs purchasing a bargain optic.
3/4/2012 6:56:38 PM
Originally Posted By 11bravo01:
That's fantastic information and anything I've ever learned has been through sites like these. I recently bought a set of 14's and I have a little bit of everything you mentioned, including a bright spot that you didn't go in to detail about. What does the 'chicken wire' determine about the tube? I've been to the range a few times with it and aside from blacking in and out, everything functions fine. I'm running on a Wilcox mount and DBAL when I use my ACH and a GG&G aimpoint twist base when I'm running it on my AR. I don't plan on using anything greater that 5.56 because as you and others have mentioned; there is no conclusive evidence that such mounts mitigate recoil to the optic as sensitive as night vision. I appreciate the information and sometimes better research outweighs purchasing a bargain optic.
That's fantastic information and anything I've ever learned has been through sites like these. I recently bought a set of 14's and I have a little bit of everything you mentioned, including a bright spot that you didn't go in to detail about. What does the 'chicken wire' determine about the tube? I've been to the range a few times with it and aside from blacking in and out, everything functions fine. I'm running on a Wilcox mount and DBAL when I use my ACH and a GG&G aimpoint twist base when I'm running it on my AR. I don't plan on using anything greater that 5.56 because as you and others have mentioned; there is no conclusive evidence that such mounts mitigate recoil to the optic as sensitive as night vision. I appreciate the information and sometimes better research outweighs purchasing a bargain optic.
Chicken Wire, as a definition in the milspec -
-
Chicken wire. Defined as a predominant pattern of dead fibers, which has a diameter not greater than 0.0009 inch (2 single fibers) whose light transmission is so degraded that with light projected through the optic, single fibers in the area in question cannot be distinguished or identified as single fibers with the use of 50-power magnification.
So it's a measure of non-functional fibers in a fiber plate. It looks like a very thin dark line when you look at it. It doesn't affect the quality of the tube - just the quality of the image it provides.
Regards
David
3/4/2012 7:06:21 PM
Originally Posted By cj7hawk:
A lively discussion isn't quite an argument and all parties usually agree on technical matters - unless the actual technical matter is either unknown or undetermined.
Originally Posted By 11bravo01:
- Anonymous Retailer
"A blemish is an obvious mark on the image
~.003mm to .015.
Anything smaller is disregarded industry wide"
Also, I'm not trying to start any arguments here as I'm seeing an increased amount of aggression over one's personal knowledge. My other question is that the typical PVS-14 weapon mount isn't truly regarded as weapon safe due to the fact that the housing threads are plastic or helicoils glued to the plastic. What about the other weapon mount platforms? Could damage occur if a mount could theoretically mitigate felt recoil to the optic itself (I.E. the LaRue STOMP)?
- Anonymous Retailer
"A blemish is an obvious mark on the image
~.003mm to .015.
Anything smaller is disregarded industry wide"
Also, I'm not trying to start any arguments here as I'm seeing an increased amount of aggression over one's personal knowledge. My other question is that the typical PVS-14 weapon mount isn't truly regarded as weapon safe due to the fact that the housing threads are plastic or helicoils glued to the plastic. What about the other weapon mount platforms? Could damage occur if a mount could theoretically mitigate felt recoil to the optic itself (I.E. the LaRue STOMP)?
A lively discussion isn't quite an argument and all parties usually agree on technical matters - unless the actual technical matter is either unknown or undetermined.
Anyway, blemish is not the correct term, just a generally used one. There's chicken wire and dark spots. Take your pick. :) It could be bright spots too, but that's another matter.
For chicken wire, any length of less than 0.003 inches ( not 0.003 mm, which is finer than the fibers of the plate and would be invisible ) are to be disregarded. For an understanding of how big that is, 0.003" is about 0.08mm, which is about 1/10th the diameter of a normal halo... So we're talking about blemishes that are very small, but big enough to notice easily.
For dark spots, any of diameter smaller than 0.003 inches are simply not recorded, however two dark spots of such size, close together so that the gap between them is smaller than the size of the spot, will be added together, eg, 0.003" dark spot plus 0.002" space plus 0.002" space is to be considered as a 0.007" blemish and counts against the tube, while either by itself would not.
This isn't something the industry decide - it's a matter of the milspec - and the above is current ( Omni VIII )
As for the PVS-14, there are two matters. The first is that the PVS-14 isn't designed for anything more than 5.56 - including the housing. That's a matter of public record and is recorded in the patent. And it goes for every part of the housing - threads, mounts, flanges... You name it.
The other matter is that some of them actually do break under higher levels of recoil.
Now the problem some of us have with anyone who claims to have a magic recoil-proof tube or housing ( lately using such oxymorons or perhaps tortologies as "Beyond Milspec" which seems to me to mean "Does not meet Milspec" since a device is either milspec or not! ) is that often the only testing done on such devices is recoil testing on a rifle - which is OK, but since they do not re-engineer the PVS-14 or determine if it can handle the recoil - tube or housing - then it's really not right to make the claim. Further, such testing is limited and does not reasonably preclude failure under tactical circumstances. For the safety of those who actually use NV in life or death situations, the only conscientious choice is to respect the manufacturers ratings and not to misrepresent the product.
That's not to say that it's impossible to make a special mount to mitigate recoil, because they do exist, but it's more just about being responsible and honest in the claims made. If a certified engineer wants to put his name to a product and claim that the product is designed for such purposes, then that's reasonable. Anything short of that, IMO, is not.
Put simply, those of us who have some level of experience in the matter like to see claims backed up by science and engineering. Not by marketing hype. And our primary motivation is the safety of people who use the equipment.
Even then, you'll find most of us support the experimenters out there. People who try to go against the grain and make a recoil-proof housing or mount. It's great that that happens. Just be open and honest about any claims you may make :)
Anyway, I hope that helps put things in perspective. :)
Feel free to question, criticise or comment on the above - :) I don't mind discussion and don't consider it to be an argument - because ultimately we all gain from accurate information... You'll find there are plenty of experts on this forum who will correct me when I'm wrong... Which happens more often than I like to admit :)
Regards
David
One of the best explanations I have ever read !!
3/4/2012 11:37:30 PM
Certainly a very interesting post for sure. I guess my final question will be if I'm limited in terms of use. Can I keep running the NODs under normal use, or should I be cautious in terms of recoil or high light conditions? I mean, that's all I really cared about anyway.
3/5/2012 12:14:26 AM
Originally Posted By 11bravo01:
Certainly a very interesting post for sure. I guess my final question will be if I'm limited in terms of use. Can I keep running the NODs under normal use, or should I be cautious in terms of recoil or high light conditions? I mean, that's all I really cared about anyway.
Certainly a very interesting post for sure. I guess my final question will be if I'm limited in terms of use. Can I keep running the NODs under normal use, or should I be cautious in terms of recoil or high light conditions? I mean, that's all I really cared about anyway.
That's actually a pretty deep question. If you use them for tactical applications, then I'd recommend that you use them as they were designed to be used. If you're using them for non-critical purposes, then it really comes down to whatever risk you're prepared to take. It's all really an odds game, so if you're not playing with your life, you can increase the risk for greater payout.
The odds aren't all that high of a critical failure of the device, so it's only money in the end. If you read these forums enough you'll find sad tales of people who have actually experienced tube failure and given that they costs thousands of dollars, it's a pretty sickening feeling. I'd never advise anyone to take that path lightly.
But it you're happy with the risk and don't mind it, you might get lucky - a lot of people have gotten away with such in the past.
Anyway, to be a little more specific: With recoil, 500G's is the limit. As an example, TNVC recommend 5.56 as do the manufacturers however TNVC has also been known to support 6.8 which has around 30% more peak recoil than 5.56. Both come in well under 500 G's. 7.62 clearly exceeds the limit. So you may get lucky or you may not. If you have enough technical data, you can skew the odds in your favor, but the average person does not have that so it's just luck.
As for high light? I wouldn't recommend specifically using your nods in high light, but in fairness, they are designed to handle it, so unless you're hit by a flare, laser or some other extreme source of light, you probably won't damage your NODs. Modern gated tubes are tested at up to 20fc, which is more than 200 lux. To put that into perspective, on an overcast, stormy day, it's about 100 lux... Office lighting is about 400 lux, so somewhere between those two. More to the point, the tubes must put out less than 4.5 fc of light, so instead of amplifying, they actually reduce the amount of light getting to your eye.
Also, Bright Source Protection is supposed to protect against looking directly at bright lights and without getting too far into how bright is too bright, the test does require that no damage occur after a minute of exposure, so we're not talking small amounts.
However despite all that protection, tube life is a parameter that is based on fairly low light levels and the more light you expose your tube, the shorter the lifespan of the tube. So to get maximum life from the tube, use it mostly under darker circumstances.
As for advice regarding use in bright circumstances? Use your NOD to best effect. If that means you will benefit by use under brighter circumstances, whether they be a full moon or looking into shadows in a bright urban environment, then do it. It might reduce tube life overall but you gain effective use of a tool and it is designed to work under those conditions - So my answer about brightness is use your head and avoid bright light exposure where practical, but I'd say to weight the benefit of using the NOD as a tool over the reduction in tube life.
Regards
David
David
3/5/2012 7:33:54 PM
David,
Thanks for all the great info. I'm currently saving up for a -14, so I've been finding it (like damn near everything you and the other experienced hands here post) to be extremely informative.
With regard to your previous post, my understanding is that, like radiation exposure to a person, high-light exposure to a NOD is cumulatively damaging. That is to say, that while there are things you can do in the short term, like leaving you NOD on in a completely light devoid area (sock drawer/ shoe box, etc.) to mitigate damage, it's still going to adversely affect the life of the tube. Would that be accurate?
Thanks for all the great info. I'm currently saving up for a -14, so I've been finding it (like damn near everything you and the other experienced hands here post) to be extremely informative.
With regard to your previous post, my understanding is that, like radiation exposure to a person, high-light exposure to a NOD is cumulatively damaging. That is to say, that while there are things you can do in the short term, like leaving you NOD on in a completely light devoid area (sock drawer/ shoe box, etc.) to mitigate damage, it's still going to adversely affect the life of the tube. Would that be accurate?
4/1/2012 11:02:00 AM
As for the PVS-14, there are two matters. The first is that the PVS-14 isn't designed for anything more than 5.56 - including the housing. That's a matter of public record and is recorded in the patent. And it goes for every part of the housing - threads, mounts, flanges... You name it.
The other matter is that some of them actually do break under higher levels of recoil.
The other matter is that some of them actually do break under higher levels of recoil.
This whole recoil thing is of great interest to me as I would like to be able to a Monocular on a .308, but all of this talk has me mre than concerned. Do you have a link to the patent? I would love to see who the inventer of the PVS-14 actually is.
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
4/1/2012 11:32:06 AM
Originally Posted By I-give-up:
This whole recoil thing is of great interest to me as I would like to be able to a Monocular on a .308, but all of this talk has me mre than concerned. Do you have a link to the patent? I would love to see who the inventer of the PVS-14 actually is.
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
As for the PVS-14, there are two matters. The first is that the PVS-14 isn't designed for anything more than 5.56 - including the housing. That's a matter of public record and is recorded in the patent. And it goes for every part of the housing - threads, mounts, flanges... You name it.
The other matter is that some of them actually do break under higher levels of recoil.
The other matter is that some of them actually do break under higher levels of recoil.
This whole recoil thing is of great interest to me as I would like to be able to a Monocular on a .308, but all of this talk has me mre than concerned. Do you have a link to the patent? I would love to see who the inventer of the PVS-14 actually is.
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
ITT invented it.
Regards
David
4/1/2012 11:52:56 AM
Originally Posted By I-give-up:
This whole recoil thing is of great interest to me as I would like to be able to a Monocular on a .308, but all of this talk has me mre than concerned. Do you have a link to the patent? I would love to see who the inventer of the PVS-14 actually is.
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
As for the PVS-14, there are two matters. The first is that the PVS-14 isn't designed for anything more than 5.56 - including the housing. That's a matter of public record and is recorded in the patent. And it goes for every part of the housing - threads, mounts, flanges... You name it.
The other matter is that some of them actually do break under higher levels of recoil.
The other matter is that some of them actually do break under higher levels of recoil.
This whole recoil thing is of great interest to me as I would like to be able to a Monocular on a .308, but all of this talk has me mre than concerned. Do you have a link to the patent? I would love to see who the inventer of the PVS-14 actually is.
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
Someone home-brewed a mount to mitigate recoil. I don't know how well it works. I'm pretty sure someone from this forum is the one that did it too. It looks nifty, but it's a lot of work. I'd rather use a head mounted NOD and a laser, or save up the coin for a clip-on. Correct tool for the job kind of thing.
This is NOT my image, just googled it. Credit belongs to someone else.
4/1/2012 12:29:44 PM
Needs a bunch of lightening holes in the base...
Since the NVD sitting behind the sight isn't alignment critical, I'd just make a foam sleeve to mount it in.
Since the NVD sitting behind the sight isn't alignment critical, I'd just make a foam sleeve to mount it in.
4/1/2012 1:30:30 PM
Originally Posted By I-give-up:
This whole recoil thing is of great interest to me as I would like to be able to a Monocular on a .308, but all of this talk has me mre than concerned. Do you have a link to the patent? I would love to see who the inventer of the PVS-14 actually is.
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
As for the PVS-14, there are two matters. The first is that the PVS-14 isn't designed for anything more than 5.56 - including the housing. That's a matter of public record and is recorded in the patent. And it goes for every part of the housing - threads, mounts, flanges... You name it.
The other matter is that some of them actually do break under higher levels of recoil.
The other matter is that some of them actually do break under higher levels of recoil.
This whole recoil thing is of great interest to me as I would like to be able to a Monocular on a .308, but all of this talk has me mre than concerned. Do you have a link to the patent? I would love to see who the inventer of the PVS-14 actually is.
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
We've had 2 broken housings (recoil related) and 2 tube failures failures from over G's.
Before the "gang" comes in, CJ7 IS correct, many years ago (it was pointed out to me and glad it was) I was using 6.8's with PVS-14's and supported that. We live and learn here at TNVC and have a training staff nowadays made up of former SF types who know more about shooting people in the face than I will ever imagine. One in which actually worked for ITT as the head of their NV training division. As Pat Rogers always say's., "Learning has occurred" and I have in regards to putting PVS-14's on high caliber weapons.
They were never ever made for this application so play at your own risk.
With that said, IF the dealer wants to warranty his PVS-14 for "shock", beyond Mil-Spec, snake oil etc. great you can break it over and over again during their 1 year warranty period. Great for pig hunters until the 1 year warranty runs out, but our first responders on a 2-way range need to know what can and does happen with a 14 on a high recoil weapon.
People ask, "Vic, could you not offer the same warranty with your PVS-14's?" Yep sure could EASILY...I could go against BOTH ITT and L3 (the actual manufacturers) and offer our own TNVC internal warranty up to .308 recoil on ANY of our PVS-14's. I could sell a metal type lens locking ring to fool folks the actual underneath plastic lens threads are somehow now super stronger along with beefing up the glue line of the 1/4-20 6 threaded Heli-Coil.
Yep, we sure could do all this and sell a ton of them and I mean a metric TON...But the day one of our first responders has a failure on a 2-way range and gets hurt because we went against the manufacturers time tested millions of dollars of analytical engineering testing, all for us to make a "sale" is the day I would never ever be able live with myself nor the families of their loved ones.
This PVS-14 stuff IS serious business, and not about hunting hogs IMHO so play at your own risk. As long as I'm still breathing and have an amazing staff made up of the guys we do (well maybe the first female soon
) , we will continue to cater to the first responders first and foremost and train and learn accordingly along with the commercial market who ask for the best and most reliable gear they can use.
Vic Di Cosola
4/5/2012 11:38:58 PM
Originally Posted By I-give-up:
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
Yes. It was ugly. Ever seen a grown man cry?
4/8/2012 6:53:40 PM
Originally Posted By I-give-up:
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
Yes. In both cases I have seen it was due to broken battery cap (2xAA version)
4/8/2012 11:30:26 PM
Originally Posted By last_lancer:
Yes. In both cases I have seen it was due to broken battery cap (2xAA version)
Originally Posted By I-give-up:
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
Also, has anyone here on this board actually broken a PVS-14 housing due to recoil?
Yes. In both cases I have seen it was due to broken battery cap (2xAA version)
LL,you can't really count breaking battery caps on the dual AA design as a failure. That is cheating because everyone knows they break all the time ! If I had to go into battle with one I would make sure I has a handful of those damn caps in my pocket.
