IR vs Thermal

[Boghog1]

So I assume there are pros and cons to each, but figure it would be nice to have a thread for experience with both or either, seems to be that pig hunters prefer thermal and prefer IR.

Has anyone used both? what is your preference?

 

[pastera]

So I assume there are pros and cons to each, but figure it would be nice to have a thread for experience with both or either, seems to be that pig hunters prefer thermal and prefer IR.

Has anyone used both? what is your preference?

IR and Thermal are pretty much synonymous unless you have the cash to go MWIR

NIR - ~680nm -> 1000nm: Invisible to the naked eye but sensed by regular silicon sensors; reflective (needs a light source to see anything)
SWIR 1000nm->1700nm: Invisible to silicon; reflective but illuminated by night glow
MWIR 3->5um: shortest heat signature (emissive)
LWIR 7-14um: cheapest heat signature as it can be uncooled

Most of us can only afford NIR or LWIR

 

[Boghog1]

IR and Thermal are pretty much synonymous unless you have the cash to go MWIR

NIR - ~680nm -> 1000nm: Invisible to the naked eye but sensed by regular silicon sensors; reflective (needs a light source to see anything)
SWIR 1000nm->1700nm: Invisible to silicon; reflective but illuminated by night glow
MWIR 3->5um: shortest heat signature (emissive)
LWIR 7-14um: cheapest heat signature as it can be uncooled

Most of us can only afford NIR or LWIR

So the green or white night vision is the same as the white/black hot or color thermal?

 

[pastera]

So the green or white night vision is the same as the white/black hot or color thermal?

Night vision is a generic term
Could be an image intensifier or an non-visual band imager or a combination

A very sensitive silicon sensor will collect a shit ton of NIR that you can't see to allow you to "see" in the dark (but only dark to you)
An image intensifier will amplify a small amount of ambient light to a level where your eye can see it - this is the classic green (GEN I intensifier). Newer micro channel intensifiers present a white image.
As for thermal, how you present the image is independent of the sensor technology so white/black hot or artificial color is a user choice

 

[JRT]

I have zero experience with IR night vision but I’ve been hunting with a thermal scope for four years now. I just upgraded to a Pulsar Thermion and the technology is way better in just that time. Forgoing the tech differences I think the biggest difference is how you use them. Night vision is attached to you and basically illuminates everything you’re looking at. I use a scope mounted to my rifle, it holds your zero in memory and you can move it between rifles and it actually holds zero. To me a thermal optic is pretty specific to hunting, animals or people I suppose. It doesn’t illuminate shit, it only shows the heat signature. IR on the other hand illuminates your world. I don’t think it treats a heat signature any different. It illuminates everything and you have to find the animal. Through a thermal it’s so perfectly outlined you know the animal like you’re looking at it in broad daylight.

 

[ChevyGuy91]

For me it is the difference between looking through an intensifier tube vs looking at a screen with a camera doing the looking for you. 2 different tools for close to the same purpose. I want thermal capability for scanning to ID heat signatures and shooting at them, but I surely wouldn't try to drive my truck with thermal. That's too much trust to put into a camera for me.

 

[JRT]

I would add that dudes with night vision are obsessed with flash suppression. I don't know if thats because they don't want a signature or if flash f***s with the tech in the tubes. I know I shot a friends cheap IR rifle mounted scope and follow up shots are not happening quick, the IR picks up by the smoke and thats all you see through the optic. With a thermal optic you don't get any interference of your image so you can shoot a follow up shot immediately.

 

[heron163]

you can make use ion thermal in the day and at night,. you can "see" in total darkness w/io any supplemental or ambient.

 

[Christian]

For me it is the difference between looking through an intensifier tube vs looking at a screen with a camera doing the looking for you. 2 different tools for close to the same purpose. I want thermal capability for scanning to ID heat signatures and shooting at them, but I surely wouldn't try to drive my truck with thermal. That's too much trust to put into a camera for me.

Thermal is no good wrt glass because all you get is the temperature of the pane of glass, not what's behind it.

 

[xtry51]

Thermal is best for target acquisition and engagement. You can pick out targets faster and identify them as basic things (human, deer, etc). You also see, VERY CLEARLY when you hit what you are shooting at with thermal. The blood mist is unmistakable and tracking hit targets is very easy.

IR/intensifier tubes are better for navigation and general everyday tasks. Better for positive ID such as "Oh that's Bob" where thermal is more like "oh that's some dude". IR is better for depth perception, better for movement without becoming disoriented or constantly tripping. IR is also better for recon woth a team as it allows things like lasers to designate a point of interest.

Ideally you'd have both. If forced to choose I pick thermal every single day. It's far more effective for engaging living things.

 

[pastera]

IR = Infra Red or frequencies below red in the EM spectrum
Medium wave and longer are emissive (you don't need ambient light to see)
Thermal is a subset of IR from medium to far.

I found a site that claims to clear up the differences but doesn't really
They call out infrared being SWIR which is very likely not true given the extreme cost of true (1-1.7 um) imagers. What they are talking about is NIR silicon sensors which simply are not what anyone would really consider more than a toy version of night vision (day extending).

The thermal imagers they are talking about are likely microbolometer based long wave units - medium cost and decent sensitivity.
Laser designators are available for all of the spectrums but NIR (980nm) and SWIR(1.54um) are cheap and easily available.

Which waveband is better depends on conditions but a thermal imager for live target detection is pretty damn good unless the target knows you are using a LWIR system and can camouflage. Add multispectral with a SWIR sensor and the vast majority of targets are visible under most conditions even if they take precautions against detection.

 

[Admin]

So I assume there are pros and cons to each, but figure it would be nice to have a thread for experience with both or either, seems to be that pig hunters prefer thermal and prefer IR.

Has anyone used both? what is your preference?

Just my .02

It depends on the application. I've seen plenty of footage of snipers using thermal and literally going to work on bad guys. If I'm moving through the woods I'm using NV if I'm static and covering a sector of fire trying to shoot "hot" things, I'm using thermal. The one thing to remember about NV and thermal, at distance if you have a little concealment and don't move there is a possibility you won't be detected by NV, there is zero possibility you won't be detected with thermal. I've called in yotes while scanning with my NV, I could hear them in the tree line but couldnt see them with NV because there was some foliage. When I looked through my thermal it was pretty instant with locating them.

 

[Uzi2]

IR requires an IR light source, ie: IR LED or IR filter on an incandescent light bulb. It detects reflection of IR light off the target and surroundings.

Thermal is passive and simply detects thermal differences and requires no light source. It is a much better method but expensive.

 

[Deleted member 12999]

For me it is the difference between looking through an intensifier tube vs looking at a screen with a camera doing the looking for you. 2 different tools for close to the same purpose. I want thermal capability for scanning to ID heat signatures and shooting at them, but I surely wouldn't try to drive my truck with thermal. That's too much trust to put into a camera for me.

This

 

[Yazz]

Break out your check book either way but a good thermal will cost more than a good IR. And a scope for a 308 or larger rifle will cost more.

 

[snd1t]

Break out your check book either way but a good thermal will cost more than a good IR. And a scope for a 308 or larger rifle will cost more.

Now you're starting to hit upon the mounted scope vs helmet mounted solution

And both have pro's/cons

Not sure I would want to have to flag anything I'm looking to observe as is necessary with weapon mounted device.

Other downside potentially is overall wear/tear/impact of recoil on a very expensive unit.

At the end of the day its all about the benjamins

If you've got nothing then going IR is best price point for getting started

 

[Oozy]

Feral hogs don't usually carry NV gear so either is good for homeland use.
However, Nam and Metascopes taught us to turn on the scope first and scan the area.
If we saw light where there was no light, somebody else out there was NV equipped. IR can see other IR gear in use.
If nothing was showing, then we'd turn on the IR light source. Heck, we even had M60 MBTs with IR searchlights on the turrets.
Impressive to be able to light up a football field and fry a chicken with that much IR output.

Starlight scopes were an improvement because light amplification needs no light source of its own. Curved eyecups fixed being spotted
by the faint green glow from the image intensifier tube on the scope user's cheek.
When the PVS-7s began being issued, another problem quickly showed itself. Two eyepieces but with a single objective lens
doesn't give the wearer true depth perception so truck drivers in convoys started rear-ending each other.
All NV gear is more or less sensitive to shock so babying it more than your Redfield or Weaver is to be expected.

Thermal imaging would be my choice if it was an issue item, but going out and buying a good one can cost you a couple of mortgage payments.
Same for repairs unless you can just turn it into depot and get another one.

 

[moojpg2]

Just get pvs31 alpha's with clip on thermal, flex on the poors.

 

[PappyM3]

One thing not mentioned yet is that a NVGs will generally have longer battery life than thermals.

My uses have been similar to everyone else here. NVGs for movement, to include assaulting objectives and conducting raids, and general seeing at night. Thermals(LWIR) for static positions used for reconnaissance and surveillance, like OPs, small kill teams, or even just outpost security.

They work great as a complimentary pair, but you can get by with just one if you need to for funding reasons.

If I could only get one, I’d go thermal (ideally a clip-on) if my main effort were hunting, and a PVS-14 monocular if I had a more contingency coverage CONOPS in mind.

 

[PaulR]

Back to top, from Shot Show I presume:

View: https://twitter.com/Shadzey1/status/1616181306697588736

 

[beltfeedm60]

So I assume there are pros and cons to each, but figure it would be nice to have a thread for experience with both or either, seems to be that pig hunters prefer thermal and prefer IR.

Has anyone used both? what is your preference?

I run both to get the job done. Where one falls short the other comes in. I kill a lot of coyotes in different states and the environment determines the best tool needed. I know it's not the best answer but the best answer is get both. Run the nods on your helmet with your ir laser for shit in a hurry but have the thermo zeroed for clean shots in shadows and when you have a little more time. Both are worth every penny.
Semper Fi.

 

[APFSDS]

I listened to this podcast on NODs before I bought mine. I also watched some youtube videos on comparisons between WP vs GP, unfilmed vs thin filmed, FOM and what goes into calculating it (and what's most important in that figure). I would recommend doing that as NODs are expensive, and "buy once, cry once" is very true.

It's my understanding that for general purpose use, best bang-for-your-buck and the most versatility, a monocular intensifier is the way to go for your first purchase. I ended up with a 2500 FOM gen 3 WP thin-filmed PVS-14. You will want a helmet mount as well (the skull crusher it may come with is suuuuper uncomfortable, I had a crye precision night cap previously that was pretty good), something I haven't gotten yet. You can use it with an IR laser or high-mount NV compatible optic if you have the NOD on a helmet mount. I eventually want a hand-held or weapon-mount thermal scope (preferably with helmet mount option I can buy or make) as well, but that is going to have to be a while, lol. That combo seems like a winner, thermal for detection and intensifier for identification and navigation.