A historical primer on weapon mounted night vision scopes
Posted 10 March 2013 - 07:19 PM
Here, we put three flashlight red lenses over the objective lens to get this one.
Posted 23 December 2014 - 07:01 PM
Since I first posted this, I have added a few more scopes and thought I would add them and their information. The first that I will add is the M2 Snooperscope / Sniperscope.
M1 / M2 Sniperscope.
The M1 / M2 Sniperscope was the WWII initial scope mounted on the M1 and M2 carbines. The biggest difference is the objective lenses with the M1 having a more bulbous than the M2. Originally, these were designed to be mounted on the T3 carbine. The T3 was a completely different rifle in that it had the mounting bar permanently mounted to the receiver not needing the bar that was used on the M1 and M2 carbines. Also, the stock was different in that the forearm area was more square to accomodate having the IR emitter mounted under the rifle.
This set-up didn't last long for several reasons. First, with the IR emitter under the stock did not permit the stock to be rested and caused the shooter to have to expose himself the height of the light to be able to see anything, not a good thing in a combat environment. Also, the T3 configuration required a separate and completely dedicated rifle that could only be used for night scope use. This wasn't found to be practical and when the IR emitter was moved above the scope, the special stock was no longer needed. It was determined that if you made a separate mounting bar, you could use a conventional M1 or M2 carbine, knock the rear sight out, cut a hole in the upper handguard and you would be in business. The configuration could be completed by any knowledgeable armorer. This example is of a M2 scope mounted on a M2 carbine with a M3 foregrip.as this rifle normally houses my M3 scope.
This picture shows the left side of the scope. You can see clearly how the cable system comes out the side of the scope, I think this is more robust than the M3. On the T3 system and some M2 modified rifles I have seen, a small bracket with a stud is mounted under the power cable to stabilize it. The M2 also come with a canvas strap to retain the scope cap in place as seen here. The IR emitter bracket is also visible on the top of the scope. This bracket is easily removable if the emitter is to be mounted under the rifle.
Posted 23 December 2014 - 07:08 PM
This is the ID tag, it is on the top of the eyepiece lens, this one made by Bell & Howell for the Corp of Engineers
The objective lens as mentioned earlier is less bulbous allowing the scope to sit a little lower providing a better profile.
Posted 23 December 2014 - 07:17 PM
The scope utilizes a six volt rechargeable battery that is mated to a power pack that converts the voltage into the higher volts necessary for operating the electron image tube. The power pack assembly was put into a standard M-1945 backpack with suspenders and a pistol belt. This power pack and battery powered both the image tube and powered the IR emitter which used the bulk of the available power. You can see in these two pictures the banana clips for mating to the battery and in the second picture, the on/off switch and the electrostatic control switch
Posted 23 December 2014 - 07:22 PM
This set of pictures shows the right side of the scope and then with the IR emitter mounted above the scope. I also placed the emitter where it would mount if it was on a T3 scope, you can see how much higher you need to hold the rifle over a berm or support for the light to work, exposing the shooter.
One note on these scopes. The first scopes weren't originally known as the M1, but as the T-120 and after the M2, the original was reclassed as the M1.
Edited by hawkdriver, 23 December 2014 - 07:24 PM.
Posted 23 December 2014 - 07:34 PM
The Snooperscope is a mount that takes a standard M2 scope so that it can be used in a pure handheld mode. This modification allows a M2 to be mounted on a mounting bar that attaches a angled handle with a push button that allows the operator to turn the system on and off with the push of the thumb button. The IR emitter is mounted on the underside of the scope. When the scope is to be used on a rifle, simply unmount the scope and mount it on the rifle. Unmount the emitter and mount it on the top of the scope and you are in business. This can be done relatively quickly
Posted 23 December 2014 - 07:37 PM
Great set up Hawk.The carbine really turned out nice.
Posted 23 December 2014 - 08:14 PM
This scope is a upgrade of the M3 Sniperscope of KW vintage. While the tube and emitter is relatively the same size as the M3, the emitter has a larger directional shroud. These scopes were still being managed by the Corp of Engineers and were made by both Varo and known as the 9903. The other made by Polan and known as the P-155. The scope shown here is a Varo model. The AN/PAS-4 was still a active system needing large amounts of IR radiation to be able to see well enough to be used, but the one difference between the PAS-4 and the M3 is that the PAS-4 was given a separate battery for the image tube so that it could be used without the IR emitter. Whenever another IR source was available, such as the Xenon searchlights on the M-60 tanks, the IR emitter of the PAS-4 could be removed. The Soviets had developed a rifle scope that could see the IR emitters and shoot at the emitters, hopefully hitting the shooter near the head. To accomplish the removal of the IR emitter, a smaller tube was placed on the outside left of the main tube. This contained the oscillator and a C-cell battery. To operate the emitter, a separate large six volt battery could be hooked directly to the emitter to power it.
Posted 23 December 2014 - 08:25 PM
The AN/PAS-4 utilizes the same mount as the later PVS-1 and PVS-2 on the M-14 and M-16. It offsets to the left of the rifle as noted in the following two pictures.
From the rear, you can see the faint glow of the intensifer through the eye shroud.
From the front, you realize how much surface area this system provides
A closer image of the ID plate
Posted 23 December 2014 - 08:36 PM
To turn the AN/PAS-4 on, you simply pull the levered rotary switch towards you one notch. This switch is on the bottom right rear of the image tube, turning the second notch turns the IR emitter on.
Once the image tube is turned on, you get the reticle pattern. My system, the reticle light is burnt out and it is a small odd sized bulb, hopefully I can find one to replace it. The image of this tube is starting to go, you can see a bright spot in the image, this is from electron burn, so it is on the downhill slide. The image is really poor compared to what we are used to today.
The reticle is introduced from the outside into the front of the objective lens like the M3, but instead of on top, it comes in from under the tube housing. It has a up and down knob and a left and right knob. The lap is inserted in the rear of the assembly and then projected into the housing.
Posted 23 December 2014 - 08:47 PM
The entire assembly comes in a fiberglass transport case, consisting of the image tube, emitter, replacement lens for the emitter. Slot for two C-cell batteries. The mounting attachment for the rifle. Two extra bulbs, and a battery carrier, cable, and battery.
As a side note, the Soviets developed their sniper rifles with a scope, the PSO-1 that had the ability to see the IR emitters of the M3 and the AN/PAS-1. The scope would provide a orangish spot when it observed high levels of IR radiation in low light situations. The sniper would aim at the orange spot and fire, hopefully hitting the IR emitter and whatever was right behind it. The PAS-4 had a short lived life before the passive systems of the AN/PVS series came along. Now that active systems are no longer used, the PSO-1 varient scopes no longer have this IR detector feature.
Posted 24 December 2014 - 07:03 AM
While I made a quick post earlier about the PVS-3, I have since acquired one, so we will update it. here.
The PVS-3 was the first real attempt to reduce the size of the scope from the massive size of the PVS-1 and -2. It is called miniaturized even though today, doesn't seem to fit. The PVS-3 is the first to use a permanent catadioptric lens. The TVS-2 took a regular PVS-2 and added the catadioptric lens for better light gathering, but the PVS-3 did it permanently. Because of this, the intensifier can be smaller. It also uses button cell batteries for it's power source reducing the size of the battery compartment. Unfortunately, someone elected to still use the side mount system instead of developing a top mount. This was the first sight that made it somewhat practical to use a NV scope on the M-16 as the PVS-2 nearly doubled the weight of the M-16.
Posted 24 December 2014 - 07:10 AM
As stated before, the sight is offset to the side and the zero function is processed through the base. The lightweight nature of the M16 makes this scope combination very hard to hold upright.
The reticle is set in a permanent position on the front of the scope, windage and elevation adjustments are made by moving the entire scope with the adjustments in the mount.
Posted 24 December 2014 - 07:43 AM
The catadiotic lens allows for the gathering of more light than a standard lens. The light is allowed to come from the front to the back curved lens. The light is then focused on the rear facing mirror that looks like a small round silver disk in the image. The image is then sent back to the front of the intensifier allowing for a smaller intensifier to get the same image as the bigger tubes int he PVS1 and -2.
The eyepiece lens utilizes the same shroud as the PVS-2, but to fit inside the plastic case, it has to be compressed and over time, they stay in this position instead of extended. Individual eye acuity is managed through setting the diopter setting here.
This scope is a Varo model with Raytheon being another big contractor for these. This is a PVS-3 that has had the MWO applied and updated to a -3A as indicated by the MWO stickers.
Posted 24 December 2014 - 08:06 AM
The power supply for this tube has truly been miniaturized, but is also it's weakest link. The battery compartment resides on the top of the tube. The on/off switch is a small toggle on the top right side and probably the weakest link of this entire scope, it is not very sturdy and a small snag would bend or break it. A single flange is next to it to protect it, but it's not very effective.
The battery compartment is opened by releasing two thumb screws, one is used as the hinge. Once opened, the door is pushed to the side exposing the battery compartment and battery tray.
A two button plastic tray is used to hold a couple of Mallory RM-930 batteries. The tray is inserted into the slot, door closed and the scope switched on.
This was a good try at reducing the size of night vision technology and it did it. However with that said, it has it's flaws. The battery trays are nearly impossible to find and the image tubes seemed to burn out easily as I have yet to find a working one.
Posted 31 December 2014 - 08:13 PM
The AN/PVS-10 was developed in the late 90's and is known as the Sniper Night Sight or SNS. The SNS is the first real attempt at a day/night sight system. The SNS was designed to be used on the M-24 Sniper Weapon System or SWS. While designed for the SWS, the SNS uses the integral rail system and can be mounted on any weapon and has been seen mounted on the M-84 .50 cal rifle. The scope has a lever on the left side that switches the scope from day use to night. The lever moves an internal image diverting mirror that when up in the day position blocks the image intensifier from sunlight damage. Also included is a high light cut-off feature. When a sensor on top of the scope senses to much light, after 70 seconds will cut off the power to protect the image intensifier. The reticle is behind the day/night optics, so regardless of which system is used, the reticle doesn't shift. The scope is rated at 800 yards day and 600 yards night.
Left and right views of the PVS-10 mounted on a AR-10 carbine.
Posted 31 December 2014 - 08:34 PM
The top of the scope contains from front to back, the distance focus knob, good from 25 feet to infinity. The gold color circle behind the focus knob is the high light cut off sensor. Six buttons on the top control the night vision.
The three buttons on the left turn the intensifier on and off and control the manual gain of the intensifier. If it's dark, by pressing the forward left button, the gain of the intensifier will increase, depressing the rear left button decreases the gain. The middle left turns the intensifier on and off.
The right side top buttons control the reticle brightness.As with the power side, the middle button turns the reticle lighting on and off. The forward increases the intensity and the back turns it down.
Posted 31 December 2014 - 08:50 PM
The right side of the scope has no functional controls as this is the ejection side of the weapon. The black oval is the back side of the battery compartment.
The left side contains the opening to the battery compartment, here shows the cap open with two AA batteries inside. The lever switch in the middle is what changes the scope from day (horizontal) to night (vertical). At the rear of the scope is the windage adjustment knob.
The objective lens is a removable 6X lens. A 10X can be installed. The lens has a mounted rubber cap to help protect the lens from dust and the intensifier during the day. The bottom of the cap is square so that when the scope is unmounted, it helps hold it upright.
Posted 31 December 2014 - 09:11 PM
The reticle adjustment turrets are on the back of the scope in front of the eyepiece on the left side and the top.
The windage is set to 1/2 MOA adjustment per click. The elevation is set for the M118 special ball ballistics with drop compensation.
The eyepiece lens allows for the eye to focus on the reticle and allows for three inches of eye relief from recoil.
Posted 31 December 2014 - 09:36 PM
The reticle is a standard mil-dot. As mentioned before, this reticle is just in front of the eyepiece and behind the day/night optics. The reticle illumination can be turned on during day or night, except it is not very effective. During the day, The scope operates much like any other day scope. I don't see the optics to be as clear as a regular sniper scope, but is acceptable. I believe that the mirror refraction is the cause of this. The picture is more because my camera can't take good pictures through the scope, this was the best I could do.
During the night, reticle is still the same, just greener.
When you turn the reticle lighting on, it lights the reticle green. I think they could have come up with a more contrasting color. If it's very light out, it is easy to lose the reticle.
Edited by hawkdriver, 31 December 2014 - 09:40 PM.
Posted 31 December 2014 - 09:54 PM
The PVS-10 is a good idea, since it doesn't require having to be side mounted like the early PVS-1 and -2 or taking the day sights away like the PVS-4. It's biggest drawback is that it weighs 4.7 pounds, causing the rifle to be very top heavy. This scope was the only attempt at a day/night scope and will probably be the last. The PVS-10 has to be returned to the factory for repair due to it's complexity and that doesn't go well with a sniper in the field.
Posted 31 December 2014 - 10:39 PM
AN/PVS-12 Aquila / M644 Raptor:
This is a rugged dedicated night vision scope designed to give good visual acquity several hundred yards. The PVS-12 Aquila is what is used for this representation. The scope has a hard aluminum body with either a 4x or 6x objective lens. This is a dedicated scope, meaning that it is designed to be mounted to a rifle, making it a night fighting weapon since normal weapon sights cannot be used with this scope. This is the last of the dedicated scopes, after this, are the "clip-on" scopes that allow for a normal scope to be used for the day and then the clip on placed in front, making a normal scope into a night scope.
The PVS-12 is fairly basic and simple to use. It has a distance focus adjustment, On/off switch, reticle brightness switch, and the usual reticle adjustments and battery pack. The scope is considered a low profile system and mounts to any rail system through throw levers.
Here, the PVS-12 is mounted on the same AR-10 as the previous PVS-10 to give a good comparative size.
The right side is devoid of any controls. The only thing on the right side is the throw lever locks. The red ring on the bottom of the objective bell is the nitrogen purge port.
The top as well is devoid of any controls
Posted 01 January 2015 - 06:57 AM
The left side is the business end of the scope, all controls are here as most shooters are right hand, this allows the right hand to focus on pulling the trigger and manipulating the bolt if on a bolt rifle. At the base of the objective bell is the focus knob. This knob has a protruding lever so you can feel the position that the knob is during dark operations, going from 25 yards to infinity. On the Raptor, this objective focus is on top like the PVS-10. On the Raptor, the control box is slightly smaller, but the battery box protrudes out and is a top load system. On the Aquila, the control box is larger with the battery box more integrated and a bottom load battery compartment. The Raptor has a screw on cap while the Aquila has a slightly harder to manipulate twist cap. Inside a protected guard is the on/off control and the reticle brightness. Interestingly, the Raptor has it's throw levers on the left side, seemingly more in the way of the control knobs.
Posted 01 January 2015 - 07:11 AM
For reticle adjustments, the Raptor has adjustment turrets that can be manipulated by fingers with the elevation on top the control box and the windage facing aft towards the shooters face which can be a little confusing as windage is typically on the side, 90 degrees to the shooters face. The Aquila on the other hand has inset click adjustments much like civilian scopes, requiring tools. This does not allow for quick adjustments in the dark, but then the theory is that you wouldn't be able to see the turrets anyway in the dark and would have to know which direction and adjust by feel. Even more confusing, the Aquila has the vertical adjustment on the bottom of the control box with the windage facing aft as well.
The eyepiece is large to give good eye relief for recoil as in the PVS-10. The diopter adjustment is by a large knurl ring that is unmarked.
Edited by hawkdriver, 01 January 2015 - 07:16 AM.
Posted 01 January 2015 - 07:39 AM
The Intensifier is Gen III, but usually a lessor grade than found in monoculars or ANVIS due to recoil. The high end tubes are built to tighter tolerances and recoil in anything over 5.56 tends to cause damage. This Aquila has a 62lp quality intensifier, but as in this image, you can see that it is still bright and gives good definition. The reticle is a small floating basic duplex lighted reticle. If the power is turned down to the reticle, there is no black reticle as in the PVS-10, the image field is just blank.
The Raptor/Aquila is a good scope, but with increasing technology, it is becoming less and less necessary for large dedicated scopes with these types being replaced by the smaller more rugged clip-on scopes. It appears as if the dedicated rifle scopes have reached the end of the road.
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