Tweet
Talk to people every day on the phone, sometimes 10+ hours a day, many have the same questions and many are confused at terms used.
One example- people confusing autoGATING with auto gain.
AutoGATING is a tube protection feature. Completely different from auto "gain" which we will discuss separately.
Autogating is technically defined as:
When the power supply is “auto-gated,” it means the system is turning itself on and off at a very rapid rate. This, combined with a thin film attached to the microchannel plate (an ion barrier) reduces blooming. While “blooming” can be noticeably less on systems with a thin film layer, systems with thicker film layers can be perfectly acceptable depending on the end user’s application.
Basically it's a tube protection feature that protects against bright light sources. It happens so quickly your brain doesn't perceive a change in the image.
You remember the movie "Patriot Games" from the 1990s? Remember when the IRA terrorists bust into the basement with old skewl PVS7's on and the captain turns the lights on and the terrorists have to rip off their NODs? That was pre-autogated tubes. Try that now and you'll just get shot in the face by the guy with NODs.
I remember when units with autogating first came out, we threw the kitchen sink at them testing the autogating- bright spot lights, six million candle power hunting lights, the strobing ground fireworks that people used to buy especially to quote "shut down the enemy's NVG" and similar BS methods that people that didn't know were still promoting to somehow "shut down" NV. All those old BS "tricks" don't work any more.
Since mid 2000's new 3rd gen and even Photonis tubes have been available with autogating. There would be NO REASON to buy a night vision set that was NOT autogated today.
Auto "gain"- So first off, what's "gain?" Here is the tech geekie definition and then I'll give the down to earth definition-
Also called brightness gain or luminance gain. This is the number of times a night vision device amplifies light input. It is usually measured as tube gain and system gain. Tube gain is measured as teh light output (in fL) divided by the light input (in fc). This figure is usually expressed in values of tens of thousands. If tube gain is pushed too high, the tube will be “noiser” and the signal-to-noise ration many go down. U.S. military Gen 3 image tubes operate at gains of between 20,000 and 45,000. On the other hand, system gain is measured as teh light output (fL) divided by the light input (also fL) and is what the user actually sees. System gain is usually seen in the thousands. U.S. military systems operate at 2,000 to 3,000. In any night vision system, the tube gain is reduced by the system’s lenses and is affected by the quality of the optics or any filters. Therefore, system gain is a more important measurement to the user.
For the NV USER, the easy way to remember it is that gain control is like the brightness setting on your phone. Say your in bed late at night and get a text. You pick up your phone and the screen is bright and immediately you feel like your retina just got a holed burned in it. So you go to settings-brightness and you turn down the brightness of the screen. That's basically what the "gain control" knob on your PVS14 will do- control the "brightness" of the tube.
"But Robert, why the heck wouldn't I want it maxed out all the time?"
Glad you asked. What happens is when gain is set too high, is that you tend to see more scintillation or the little "snow" looking stuff and you actually tend to degrade the image quality. So it's important to find that happy medium wherein the image isn't degrade but your getting the most out of your tubes. It's going to be different every night and in varying light conditions. In other words, it's something you will check every time you first put on NODs.
Manual gain control = being able to control the gain on your unit.
So what is "auto gain?" Actually auto gain should be called what it really is: no gain control. On an 10160 tube style there is no "pigtail" that allows the unit to have manual gain. The gain is set high for at the factory and you can't change it.
So when you see "auto gain" understand that is really means No gain control. Typically you see "auto gain" (remember that means No gain) in dual tube sets, most of which utilize the 10160 tube format which doesn't allow gain control.
Auto gain = No gain and is different from autoGATING.
Knowing these terms and differences will help you when shopping for NV and "comparing", etc.
One example- people confusing autoGATING with auto gain.
AutoGATING is a tube protection feature. Completely different from auto "gain" which we will discuss separately.
Autogating is technically defined as:
When the power supply is “auto-gated,” it means the system is turning itself on and off at a very rapid rate. This, combined with a thin film attached to the microchannel plate (an ion barrier) reduces blooming. While “blooming” can be noticeably less on systems with a thin film layer, systems with thicker film layers can be perfectly acceptable depending on the end user’s application.
Basically it's a tube protection feature that protects against bright light sources. It happens so quickly your brain doesn't perceive a change in the image.
You remember the movie "Patriot Games" from the 1990s? Remember when the IRA terrorists bust into the basement with old skewl PVS7's on and the captain turns the lights on and the terrorists have to rip off their NODs? That was pre-autogated tubes. Try that now and you'll just get shot in the face by the guy with NODs.
I remember when units with autogating first came out, we threw the kitchen sink at them testing the autogating- bright spot lights, six million candle power hunting lights, the strobing ground fireworks that people used to buy especially to quote "shut down the enemy's NVG" and similar BS methods that people that didn't know were still promoting to somehow "shut down" NV. All those old BS "tricks" don't work any more.
Since mid 2000's new 3rd gen and even Photonis tubes have been available with autogating. There would be NO REASON to buy a night vision set that was NOT autogated today.
Auto "gain"- So first off, what's "gain?" Here is the tech geekie definition and then I'll give the down to earth definition-
Also called brightness gain or luminance gain. This is the number of times a night vision device amplifies light input. It is usually measured as tube gain and system gain. Tube gain is measured as teh light output (in fL) divided by the light input (in fc). This figure is usually expressed in values of tens of thousands. If tube gain is pushed too high, the tube will be “noiser” and the signal-to-noise ration many go down. U.S. military Gen 3 image tubes operate at gains of between 20,000 and 45,000. On the other hand, system gain is measured as teh light output (fL) divided by the light input (also fL) and is what the user actually sees. System gain is usually seen in the thousands. U.S. military systems operate at 2,000 to 3,000. In any night vision system, the tube gain is reduced by the system’s lenses and is affected by the quality of the optics or any filters. Therefore, system gain is a more important measurement to the user.
For the NV USER, the easy way to remember it is that gain control is like the brightness setting on your phone. Say your in bed late at night and get a text. You pick up your phone and the screen is bright and immediately you feel like your retina just got a holed burned in it. So you go to settings-brightness and you turn down the brightness of the screen. That's basically what the "gain control" knob on your PVS14 will do- control the "brightness" of the tube.
"But Robert, why the heck wouldn't I want it maxed out all the time?"
Glad you asked. What happens is when gain is set too high, is that you tend to see more scintillation or the little "snow" looking stuff and you actually tend to degrade the image quality. So it's important to find that happy medium wherein the image isn't degrade but your getting the most out of your tubes. It's going to be different every night and in varying light conditions. In other words, it's something you will check every time you first put on NODs.
Manual gain control = being able to control the gain on your unit.
So what is "auto gain?" Actually auto gain should be called what it really is: no gain control. On an 10160 tube style there is no "pigtail" that allows the unit to have manual gain. The gain is set high for at the factory and you can't change it.
So when you see "auto gain" understand that is really means No gain control. Typically you see "auto gain" (remember that means No gain) in dual tube sets, most of which utilize the 10160 tube format which doesn't allow gain control.
Auto gain = No gain and is different from autoGATING.
Knowing these terms and differences will help you when shopping for NV and "comparing", etc.