Night vision goggles

[Ockham's Spoon]

I am making some agent types up, and I have a question for anyone who knows about real-world night vision goggles.

 

Obviously they let you see in low light levels, but do they compensate for high light levels or do they just saturate? Could a wear a pair all the time so I could see both day and night?

 

If I wear night vision goggles during a thunderstorm and there is a nearby lightning flash, will I be blinded by it? That is, in game terms, would I acquire a Vulnerability to Light-based Flash attacks while wearing the goggles?

[Christopher]

Re: Night vision goggles

 

I had some problem undertsanding their dialect, but I think actual (digital) night vision googles don't suffer such problems anymore:

http://news.bbc.co.uk/2/hi/technology/8363411.stm

[Bloodstone]

Re: Night vision goggles

 

I am making some agent types up' date=' and I have a question for anyone who knows about real-world night vision goggles.[/quote']

 

I use NVG's regularly. Makes everything green; the sort of night vision that you normally see in movies and video games, though there are other technologies available.

 

Frankly, they kinda suck without the illuminator switched on (which is basically an attached IR flashlight), which is obviously not a good idea if someone else has IR vision capabilities...

 

Anyhow, if that is the sort of tech you are going for I can offer some insight or even conduct some tests for you.

 

But this isn't expensive, cutting edge equipment so not sure how useful that insight would be...

[Christopher]

Re: Night vision goggles

 

I use NVG's regularly. Makes everything green; the sort of night vision that you normally see in movies and video games, though there are other technologies available.

 

Frankly, they kinda suck without the illuminator switched on (which is basically an attached IR flashlight), which is obviously not a good idea if someone else has IR vision capabilities...

IR is just "seeing light that normal people can't see" and that isn't as easily absorbed by the atmosphere and part of the starlight/moonlight. If you don't have some source of IR-light (say a closed room) you would be as blind as without them.

 

If it is really dark you propably switch to Thermal Vision:

http://en.wikipedia.org/wiki/Thermal_Vision

[Bloodstone]

Re: Night vision goggles

 

IR is just "seeing light that normal people can't see" and that isn't as easily absorbed by the atmosphere and part of the starlight/moonlight. If you don't have some source of IR-light (say a closed room) you would be as blind as without them.

 

I know. That's what the illuminator is for...

 

If it is really dark you propably switch to Thermal Vision:

http://en.wikipedia.org/wiki/Thermal_Vision

 

Assuming said agents are operating at that tech level. ENVG's are very expensive and relatively recent tech. Of course, the agents could be carrying around separate devices for thermal and low-light, which would still be an expensive option and would require lugging around extra equipment.

 

Of course, if this is supposed to be for a comic book tech based game, this is probably a non-issue as you can fit all this stuff into the lenses of a standard superhero mask

[Folded]

Re: Night vision goggles

 

I think that if you are going for moderately realistic, then a one-mode-at-a-time option is best. For normal vision, flip the goggles up. Light Amplification provides Nightvision where there is light present at least equivalent to starlight on a partially clear night. Thermal uses the IR Vision Sense. Probably not feasible to have both in one unit in real life, but certainly handwavable in game. The unit will be bulky, so penalties to various rolls would be entirely appropriate (OCV, DEX, Hearing, maybe general Perception).

 

Remember that IR can have problems discriminating between objects of similar heat levels, depending on its sensitivity. Trying to cross a room where all of the objects within it have come to approximately the same temperatures can be difficult. LA has the problem that one can't distinguish colors while using it, and contrast can be a serious issue, as can response time to large shifts in general illumination (provides Flash Defense to the character, but is disabled itself as if Flashed, or something like that).

 

If you want to push it further, add modes for Active Sonar and/or Radar. Neal Stephenson uses millimeter-wave radar frequently in his books, although it is far less effective in reality for a variety of reasons.

[Bloodstone]

Re: Night vision goggles

 

Probably not feasible to have both in one unit in real life' date=' but certainly handwavable in game.[/quote']

 

Oh, it's quite feasible if you have about $10K to toss around per agent:

 

http://www.youtube.com/watch?v=zGXbgWqpiUw

 

But as I said, that's pretty new tech and not exactly readily available...

[Folded]

Re: Night vision goggles

 

Oh, it's quite feasible if you have about $10K to toss around per agent:

 

But as I said, that's pretty new tech and not exactly readily available...

 

I stand very corrected. That definitely goes on the list of things I'll buy when I win the lottery.

[Ockham's Spoon]

Re: Night vision goggles

 

Thanks for the feedback. In game terms it looks like standard NVG would just be +4 PER only to offset darkness modifiers, while thermal imaging is obviously Infrared Vision, possibly with a Active source. From the video, it looks like they can operate during the day without problem.

 

For the game I could certainly leave it at that. I am curious to know though if real-world technology would make NVG wearers vulnerable to light-based Flash attacks. If my players are clever enough to think of that, then I think they should benefit (although the next generation NVG for the agents might compensate for that). But if current technology already has a saturation buffer or something to prevent blindness from excessive light, then that would be less appropriate.

 

Also, if NVG give a vulnerability to Flash attacks, is it a function of the eye or the electronics? Does excessively bright light temporarily screw up the NVG or is the wearer really blinded by an enhanced Flash?

[Christopher]

Re: Night vision goggles

 

For the game I could certainly leave it at that. I am curious to know though if real-world technology would make NVG wearers vulnerable to light-based Flash attacks. If my players are clever enough to think of that' date=' then I think they should benefit (although the next generation NVG for the agents might compensate for that). But if current technology already has a saturation buffer or something to prevent blindness from excessive light, then that would be less appropriate.[/quote']

Well he might be succeptible for a Flash targetting Infrared Sense. As far as I undrstand, all other light is filtered. The problem is that Hero doesn't let's you mimic that easily (by default flash targets an entire sense group).

 

Also, if NVG give a vulnerability to Flash attacks, is it a function of the eye or the electronics? Does excessively bright light temporarily screw up the NVG or is the wearer really blinded by an enhanced Flash?

When it has electronic, I would say the electronic is flashed. Since you don't see the image but a re-creation of the image, you would have to:

a) build in a monitor/lense that is strong enough to flash you

leave out something as simple as a "filter peaks" algorithm. Filtering out values over a certain (not hardcoded) threshold is something I can do with three commands in BASIC/MIXAL and other porcessor languages.

[Ice9]

Re: Night vision goggles

 

I think they would actually give you Flash Defense, with a Side Effect (minor, always occurs; goggles are disabled for the Flash duration). If the goggles reset quickly, the disabling could be for a shorter time; or conversely if they're delicate they could be disabled until manually recalibrated.

[Christopher]

Re: Night vision goggles

 

I think they would actually give you Flash Defense' date=' with a Side Effect (minor, always occurs; goggles are disabled for the Flash duration). If the goggles reset quickly, the disabling could be for a shorter time; or conversely if they're delicate they could be disabled until manually recalibrated.[/quote']

I would build it similar to te Sonar/radar of a ship.

Buy a complete normal Sight sense with the Night Vision Bonus, but with "Only affected as IR and Thermal Vision, not Sight -0", "Blackout (normal Sight) -0", OAF. maybe add "Real Nightvision" for all the other small things.

 

To mimik the "only flashes normal sight/only flashes Nightvision" correctly you would need to apply "limited Effect" from 6E1 160 to most Flashes/Sense affecting powers.

[Bloodstone]

Re: Night vision goggles

 

Thanks for the feedback. In game terms it looks like standard NVG would just be +4 PER only to offset darkness modifiers...

 

Not quite.

 

NVG's not only enhance existing light, they also let you see infrared light, which is why my NVG's have in illuminator (IR flashlight) built into them. That way, I have an active source of light that people without NVG's can't see. Of course, the disadvantage of that is that someone that can perceive IR light can see the illuminator, so if I turn it on I'm giving away my position just as surly as if I were waving around a normal flashlight.

 

Now, that said, being able to perceive IR is not the same as thermal imaging (which is what Infrared Vision is in game terms)

 

Here's a video to compare and contrast:

 

 

Do you have access to Dark Champions? There's a pretty decent write up for standard NVG's on pg 276.

 

It doesn't cover all the disadvantages of the things though: limited field of vision, reduced range/sharpness of vision, problems with depth perception, over saturation... and I have no idea what the technical term for the puddle mirage thing is (puddles sometimes look like holes in the ground)

 

while thermal imaging is obviously Infrared Vision, possibly with a Active source.

 

Not that I've ever seen. Thermal imaging strictly reads background heat AFAIK.

 

From the video, it looks like they can operate during the day without problem.

 

My NVG's can't. The screen blacks out if they are exposed to too much light. Come back pretty quickly once the light source fades though.

 

Not sure how it works on newer models.

 

A device that's relying purely on thermal imaging should not have any problems during daylight operation though.

 

For the game I could certainly leave it at that. I am curious to know though if real-world technology would make NVG wearers vulnerable to light-based Flash attacks. If my players are clever enough to think of that, then I think they should benefit (although the next generation NVG for the agents might compensate for that). But if current technology already has a saturation buffer or something to prevent blindness from excessive light, then that would be less appropriate.

 

Also, if NVG give a vulnerability to Flash attacks, is it a function of the eye or the electronics? Does excessively bright light temporarily screw up the NVG or is the wearer really blinded by an enhanced Flash?

 

Sorta. This is something I'd really have to test out to be sure.

 

I've had a flashlight shined in my eyes while I was using mine. It was rather blinding, but it would have blinded my without the NVG's on too. As such, I'm not sure how much worse the NVG's made it.

 

However, as I said, the NVG's will black out in the presence of too much light and won't come back until the light fades. For example, if I try to look up in the sky on an overcast day, they will turn off, even though I can look around at the ground just fine.

 

Like a regular flashlight, the illuminator also isn't doing anything in high light conditions as there's so much IR light that it just fades into the background.

 

Also, keep in mind that using NVG's temporarily kills your natural night vision because you are essentially staring at a bright green monitor while using them. Your eyes need time to readjust to the darkness if you take them off or if they shut off. This is something the players could probably take advantage of.

[Bloodstone]

Re: Night vision goggles

 

And I want to stress that we have folks posting here that have most likely used newer tech than I have and could thus offer better insights....

 

(probably Teflon Billy for one)

[Ockham's Spoon]

Re: Night vision goggles

 

Passive NGV would not have the IR flashlight, while active ones would, true? The active ones can operate in complete darkness since they provide their own IR light source but then you can be seen more easily by others with NGV or thermal imaging. Good enough.

 

So would I be correct in saying thermal imaging covers a larger chunk of the spectrum which is what lets you see body heat and whatnot at longer wavelengths?

 

I know someone with the 5th edition Hero Equipment Guide which I think has the Dark Champions equipment in it; I will have to check on NGV in there. Thanks.

[Folded]

Re: Night vision goggles

 

Some minor points occurred to me, based on above posts:

 

1) Day use - don't need them, which is why every version I've seen allows you to move the unit away from the eye while leaving it in place on the mount.

2) Losing natural night vision can be a real problem, which is why (I think) the newest units shown in one of the videos linked to above only covers one eye. That allows the other eye to remain dark-adapted (or at least mostly so). Full dark-adaptation takes about twenty minutes, due to differences in adaptability between cones and rods (http://en.wikipedia.org/wiki/Dark_adaptation).

3) Seeing in the dark is not the same as having full stereoscopic vision in the dark. It may be worth considering, in terms of ranged attacks, fast movement, determining distance and so forth, or it may not. Depends on how realistic/complicated you want things.

[Bloodstone]

Re: Night vision goggles

 

Passive NGV would not have the IR flashlight' date=' while active ones would, true?[/quote']

 

No, in HERO terms, NVG's are Passive senses, just like normal vision is. They will pick up ambient IR light if there is any to be seen.

 

This is why the illuminator would be built like a normal flashlight (ie using Images to provide a perception bonus that only applies to beings that can see IR)

 

So would I be correct in saying thermal imaging covers a larger chunk of the spectrum which is what lets you see body heat and whatnot at longer wavelengths?

 

I'll try to explain the differences to the best of my ability, which is pretty basic in the grand scheme of things...

 

NVG's work on two levels. The first is that they magnify existing light. The second is that they lets you perceive objects that are reflecting IR radiation, just like how our normal color vision lets us perceive objects when visible light radiation bounces off them. As such, NVG's will not work in total darkness without an illumintor

 

With NVG's, everything shows up green because that's the way the screen is designed to work. We could make it all show up as red or blue instead, but most humans have a better ability to perceive different shades of green than they do other colors. So the green screen provides us with better image contrast.

 

Because it's working with reflected light (albeit some of it light we can't normally perceive), I can read a book, watch a movie or see my reflection in a mirror while using my NVG's. NVG's perceive the shadows objects cast, which can be a benefit or a disadvantage depending on what you want to do (you can't hide in a shadow if you can't tell it's there, for example)

 

Overall, it's fairly simple technology and not all that different from our normal vision.

 

Thermal imaging works totally differently. This is where my first hand experience goes down considerably, as I've only played around with the stuff a little bit here and there. I don;t own any equipment that does this and have used a pair of imaging goggles. Everything I've used with thermal imaging was on either a hand held scanner or a stationary computer display.

 

But here goes anyhow..

 

In simple terms, a devices thermal sensors read the heat signature of an object. This is the radiation that an object actually emits, as opposed to what it reflects, making light sources largely irrelevant. This is a passive sense in HERO terms.

 

Using that info, the computer in the device then assembles a visible light image that is displayed on a monitor of some sort. This is usually done in false color (ala the Predator) or in gray scale (as in the vid above).

 

This provides us with a accurate 3D model of whatever we are looking at, with the contrast determined by the heat an object emits. This is why thermal imaging can cut right through smoke and fog, whereas NVG's are still impeded by it like normal vision.

 

With thermal imaging you can perceive differences in shape, depth and sometimes a sense of texture. Depending on how accurate the sensors are and how close the target is, you can generally tell people apart. At longer distances, a persons hair style will stand out more than facial features. Skin color may as well not exist in thermal, because you can't see light dependent details. This includes the print in a book/map or the picture on a tv/monitor. They all have essentially the same temperature, so the sensors don't perceive the differences.

 

Sure, now you can see that guy hiding in the bushes. He stands out like a neon sign because he's so much warmer than his surroundings. But you can't really perceive the individual leaves of the bushes as it's just a big black mass until you get closer. This can also make it hard to tell friend from foe if they are wearing similar clothing...

 

Normal glass is particularly interesting, since it isn't transparent to heat quite the same way it is to light. A pair of reading glasses may as well be sunglasses and the window on a building just looks like a differently colored section of wall. Car windshields can conceal the identity of the occupants.

 

With thermal imaging, lights do little to nothing to illuminate the object they are shining on, as they are not significantly changing the objects temperature. So the actual flashlight will show up in someone's hand because of the heat difference between hand and metal tube/bulb, but you won't actually see the beam itself.

 

Of course, you can also do neat things like see the heat people leave behind when they touch something. But that probably requires more sensitive devices (and things like the Tracking adder in HERO terms).

 

The ENVG I showed off above seek to take all the benefits of both technologies and combine them into one unit.

 

And that was much longer winded than I intended... and hopefully largely accurate...

[Christopher]

Re: Night vision goggles

 

Passive NGV would not have the IR flashlight' date=' while active ones would, true? The active ones can operate in complete darkness since they provide their own IR light source but then you can be seen more easily by others with NGV or thermal imaging. Good enough.[/quote']

NGV is a passive Sense.

It's just that some have the "Flashlight" Power from 6E1 238 with an additional (Only Infrared; -1/4) Limitation montaged into the same focus. As far as I understand the IR-Visions is very short range. You can't see anything beyond your light sources range, just like normal sight can't see beyond what the Visibile Light Iluminates.

Don't know if they pop up on Thermal Imagaing any more than anything else.

 

So would I be correct in saying thermal imaging covers a larger chunk of the spectrum which is what lets you see body heat and whatnot at longer wavelengths?

As I understand Thermal Imaging measure in way lower wavelenghts of the IR-Spectrum (down to -50° rather than +250°). And the result isn't given unfiltered/unprocessed. Instead the computer/electronic calculates the differences between the emited energy and thus the temperatures. But it has do be set to a narrow area or range of temperatures and only sees in those.

 

In fact I even think thermal vision is best build using a "Detect heat" as part of the touch sense group (and asume objects block it).

 

The nightvision (+4 PER to counter darkness) is what Superheroes use to see in the dark, beacuse they don't want to delve that deep into the area of realism.

[Sean Waters]

Re: Night vision goggles

 

I had some problem undertsanding their dialect, but I think actual (digital) night vision googles don't suffer such problems anymore:

http://news.bbc.co.uk/2/hi/technology/8363411.stm

 

 

Well the reporter was just BBC English, the guy with the 'other' accent is from Northern Ireland. Good signpost!

[Bloodstone]

Re: Night vision goggles

 

I've had a flashlight shined in my eyes while I was using mine. It was rather blinding' date=' but it would have blinded my without the NVG's on too. As such, I'm not sure how much worse the NVG's made it.[/quote']

 

Something I totally meant to mention here, but didn't

 

While a flash of bright light can be blinding with NVG's on, even lower amounts of light can really be a problem.

 

Take a look your standard red and white exit sign some time.

 

This is not something anyone would consider "bright" with normal vision, even in a dark room.

 

My NVG's will magnify this to the point that it's a glowing sun like beacon!!!!

 

Ok, I exaggerate slightly. It's not blinding, but it's not something you want to stare at for any length of time. The red letters actually become completely illegible due to magnified the background light is.

 

Larger, brighter lights actually give off enough radiance that you could probably hide in plain sight by standing next to or behind them.

 

And again, newer tech probably handles this kind of saturation better...

[Ockham's Spoon]

Re: Night vision goggles

 

Great information guys. Thanks for your help.

[Sean Waters]

Re: Night vision goggles

 

One quick point: Hero deals with 'nightvision' as a +4 sight PER (or deals with 'night' as a -4 sight PER): that has to assume that there is some light. That sounds like a 'standard' Light AMPlification system. For older generation goggles you could build it with a 'blinded' side effect when exposed to bright or coherent light.

 

The 'thermal' goggles they mention can probably be dealt with by way of just adding IR vision to standard sight group (you can probably even see writing if it is big enough as the black ink will radiate more heat than the white paper).

 

Both builds are pretty cheap, but IR is actually cheaper (5pts) than +4 with sight PER (8 points), although you could and probably should bring down the cost with a limitation (only to overcome sight penalties due to dark conditions) which the book pegs at -1/2, but I feel it is probably worth more like -1: I mean you are probably spending more time in the light than in the dark. At -1/2, enhanced PER costs the same as IR vision but is probably less effective: it can not, for example see in total darkness, which is going to be far more common than an environment with a completely uniform temperature.