If you have ever seen the movie Predator, I am sure you contemplated what it would be like to see in thermal vision. To be able to spot prey no matter the time of day, forest cover, or anything else they could do to hide from you. Let’s not pretend that its cheap to get access to that alien technology but with some smart decisions, you can easily get the best thermal scope for the money!
Its still going to cost, there are no cheap thermal scopes, but as long as you understand what you need and what you want from a thermal rifle scope, you can get one that suits you well and perhaps even at a price you can live with. That is provided it works well for you, they may not be cheap but you can always get a value thermal scope if you look in the right place.
To help you sort through the technological mess, let’s take it one step at a time.
- Why do you need a Thermal Imaging Scope?
- How does a Thermal Scope Work
- Thermal Scope Purchase Considerations
- Top 9 Thermal Scopes 2019 - Comparison Table
- Top 5 Thermal Scope Reviews
- Thermal Scope Accessories
- Thermal Scope Brands
- Pros and Cons of a Thermal Scope
- Thermal Vs Night Vision
- How to Zero a Thermal Scope
- Thermal Scope Hunting Tips
Why do you need a Thermal Imaging Scope?
The truth is that most people will never need a thermal scope but there are a few select people that do use a thermal scope for hunting and it makes all the difference. You won’t be target shooting with a thermal scope, the way they work most targets wouldn’t show up. You can use one for home defense and security and they do a superb job that no other tool can do.
Like the famous alien from the movie, if you are a sportsman, using a thermal scope for coyote hunting will make you the most effective you could ever be in the dark. Living this will light up like a candle in the night. This is my preferred use where I live but many people opt for a thermal scope for hog hunting and do every bit as well as I do with coyote.
If you want to elevate yourself to the true apex predator as you should be, you have to conquer the night. Sure, you can do that with a standard night vision scope but they do not perform as well as thermal scopes. This is the pinnacle of technology when you need to see what’s hiding in the dark.
How does a Thermal Scope Work
Both digital night vision and thermal optics work using infrared light. This makes things confusing between the two but there is a clear difference in how they work. To understand this, you need to understand that IR light is a range falling into three categories:
- Near IR is very close to visible light and is what a digital night vision optic relies on. This light is not visible to humans but behaves just like visible light. This means it reflects and is emitted normally. You can get flashlights that shine in Near-IR.
- MID IR is the upper reaches of what a digital night vision scope uses. This works much the same as Near IR but has a longer wavelength and travels farther.
- Thermal IR is the farthest away from visible light and is emitted from all things in the form of thermal radiation. This has the longest wavelength and travels the farthest. This is what a thermal optic picks up.
What happens when this invisible thermal IR light hits the optic is quite complicated and very technical so we will stick to the brief explanation.
Inside what you would normally think of as the lens is actually a phased array of IR detectors. Because they are phased, they can send a variable signal depending on the intensity of the thermal IR that is hitting them. This allows the internal computer to establish a pattern of heat values in the scope's view called a Thermogram.
This thermogram is transformed into a series of electrical impulses which are processed through the internal computer of the thermal-optic and converted into a raster display. This just means a grid with each cell representing a value.
This raster is just like the images you see on your computer screen. Each cell value will represent a pixel or series of pixels on the output monitor. The entire process is to take an invisible image composed of thermal IR and translate it to an image in visible light. Because the light is not reflected but instead emitted from your target, there are no color values unless it is done by the onboard computer.
That is a brief and over-simplified explanation of how thermal optic function and how they display the data they receive.
Thermal Scope Purchase Considerations
There are a lot of factors that go into deciding on a scope and ultimately, a thermal scope is likely the most advanced tool you will ever buy for hunting. But most of what happens inside the scope isn’t that important for a layperson to understand. As long as you can get the basics of what you get out of a scope, you will do fine.
Unlike traditional night vision scopes, the range on thermal is far better with sometimes more than 1000 yards on some of the best units. This is hardly necessary for most hunters but consider the ranges you hunt and get a magnification that works. Most scopes top out around 15x. Its common to see less than 5x on a budget thermal scope.
Far more important than the magnification is the sensor resolution. Think of this like camera resolution on a digital camera. You aren’t going to get anywhere near megapixel range with thermal and you don’t need it. What you are going to see is a blob of color and not detail so don’t worry about it. You are more concerned about shape.
That said, if you are a hunter you need good shot placement. To get that, you need to be able to distinguish between the parts of an animal and you are going to need decent resolution to do that. You can expect a modest to good scope to have a 640x480 resolution. If it gets below a 320x240, you are going to have trouble.
This somewhat ties into magnification but should be listed separately. The sensitivity of the thermal detector will determine how far away it can actually pick up thermal radiation. You want something farther than you plan to hunt optimally. This allows you to scout with your scope and even watch your target approach as you wait for that perfect shot.
Some rifle scopes will have ranges out past 1000 yards but a more modest scope will be in the 300-500 range. Either will usually be acceptable to most hunters. You really don’t need to shoot more than a couple hundred yards after dark anyway for safety reasons.
The overall toughness of any outdoor product should always be a factor. It will have to contend with dust, rain, fog, occasional rough treatment, and anything else the environment wants to throw at it. Getting something that will last is a paramount concern. A warranty is also a plus and comes with many units.
A thermal vision scope is a high-tech and quite sensitive piece of equipment. They will always need to be treated with some care. You aren’t going to get one that you can beat around like your grandpa’s shotgun but you can get something that will do the job in adverse conditions. Be cautious of low-end scopes and their ability to hold up over time, you need to get your money’s worth out of a thermal scope.
Being high-tech, that means there are a lot of extras that can be packed into a thermal scope. These can be the simple things like changeable reticles all the way up to video recording. Every brand has its niche and some offer very advanced options like rangefinders, inclinometers, and GPS.
Some of these are sales gimmicks but some are legitimate features. Though it may not be a concern to me, having a scope that can stream to your smart device over Wi-Fi may be something you see a value in. Judge each scope independently and don’t sacrifice overall quality for these extras. They do add to the cost so be prepared for that.
Top 9 Thermal Scopes 2019 - Comparison Table
Top 5 Thermal Scope Reviews
Trijicon TEO Reap-IR
What’s not to love about an optic made by Trijicon? They make the best of the best in every class of optics they produce and despite their being very new with thermals, this is an astounding success! If you are after the best thermal on the market, you have found it. This is one of the few that is mil-spec and ready to go in any environment.
The resolution on this optic is 640x480 and the zoom goes from 2.5 to 20x to give you the maximum amount of versatility. Anywhere from long distance hog hunts to short range CQB, this scope excels. To maximize its potential, there are not extreme color modes. You get an option for white or black hot but as an added bonus, you can choose an outline mode that will highlight targets while not ruining your night vision.
The whole concept of the Reap-IR is to provide a small, lightweight optic with a lot of power. This it does in spades while still being easily the most durable thermal optic on the planet. If it can handle the harsh desert environments and urban streets, it should be able to do anything you need for deer hunting or any other purpose that comes to mind.
While extras aren’t the focus, there are a few that are quite handy. Firstly, this optic has an integrated rangefinder. This is coupled with a readout showing exactly where your reticle is pointed. There are a few different options on how your sight appears and all of these functions are easily controlled by a single thumbstick. If you want the best, this is absolutely the sight you want.
Pulsar Trail XP 1.6
With so few competitors in the thermal optics market, every brand has its own fame. That said, I am not sure anyone could have expected Pulsar to come out with such a phenomenal optic. This is the best if a series of optics from Pulsar and easily the best of the bunch. If you want power and accuracy, this scope combines them in spades.
To get the specifics out of the way, the resolution is the high side at 640x480 and magnification goes from 2 to 13x. None of that is outstanding but when you see that the detection range on this optic is nearly 2000 yards, it begins to look a little different. While it is highly unlikely that you will ever even want to shoot that far in the dark at a tiny target with a 12x scope, that detection range allows you to spot targets before they are ever in range.
This has all the standard durability features, it resists water and fog. The whole scope is dustproof for use in harsh environments. With Pulsar, this is par for the course. You also get an amazing 8 hours of run time and the option of adding a battery pack that will take it up to 20 hours or more depending on your settings. Plenty to hunt all night and then some.
When it comes to extras, Pulsar essentially has them all. You get a picture in picture zoom to get a tight view while still seeing the full scene. You can send your video stream to an external device. Combine this with a remote control and you have a way to see through the scope without even needing to be at the gun. Easy mount, easy zero, this is truly an amazing piece of technology.
3 ATN ThOR HD 640
When it comes to thermal optics, there are only a few companies to choose from. The one that comes up the most is made by a company that is well known for their highly advanced range of optics, ATN. Not only is the ThOR HD the best thermal scope under 5000 bucks but incorporates some of the best technology and innovations on the optical market today.
Starting with the thermal scope its self, it has the industry standard 640 resolution with a large variety of selectable reticles and plenty of pallet choices to provide you the best color scheme for any environment from two-tone to classic rainbow patterns. Even in the densest fog or heaviest rain, you can easily see any living prey. The ThOR HD comes in a variety of powers from a max 5x to a max 50x.
Even though its high tech, the ThOR is designed for hard use in adverse conditions. Its unaffected by moisture and handles shock well on any rifle up to 30 caliber. The attached lens caps keep your investment safe and the rubberized buttons make manipulations of this scope easy.
When it comes to extras is where the ThOR HD starts to shine. Not only is it an amazing thermal optic but comes equipped with a rangefinder, GPS, customizable ballistic calculator, and can even record HD video directly through your scope. It can send this video over Wi-Fi to any device (IOS or Android) so you always have a record of your hunt or have a friend spot for you in real time straight from your scopes view.
4 Pulsar Trail XQ
Pulsar is an up and coming company and the new kid on the block when it comes to thermal optics. But this doesn’t make the Trail XQ any less of a good optic, quite the opposite. This is a stellar quality scope and even more amazing since it is the first scope that Pulsar has released.
The Trail starts with a high res 640x480 AMOLED display and builds its scope out from there. With a max of 10.8x magnification and an astounding detection range just shy of 2000 yards, there is nothing that can hide from this scope. Select from 13 reticles that feature a 1 shot zero and up to three profiles for different rifles so you can mix and match.
The Pulsar is IPX7 waterproof and unaffected by fog or dust. It can handle a beating in most rifles smaller than a magnum round and run all night long. As a matter of fact, the 8 hours run time is among the best in thermal optics and actually beats out most standard night vision for runtime. It even comes with a charger and of course the all-important warranty.
Just like with the ATN, this scope revels in its options. It can stream to a smart device using the proprietary Pulsar Stream Vision app for all the benefits that entail but it also comes with a remote. Meaning you can scan with this scope using a smart device and the remote control.
It even comes with detection software to help you spot targets in the densest cover. For a new company, Pulsar is doing just about everything right.
Not only does Armasight use FLIR technology but they are made by FLIR, the original and only manufacturer of high-end thermal detectors. All of these optics use them but this scope was what they were designed for and FLIR makes the most of the design and knowledge they have gained over the years.
The Zeus is 3 to 12x optic which is nothing spectacular and it is a lower res 336x256. While this doesn’t seem to stand out among the crowd, there is a massive amount of technology behind this optic that pushes it over the edge. With contrast, gain, sharpness correction handled by a computer and a flat-field correction to keep down image noise, this is a remarkably clear scope.
In all respects, FLIR is used to operating in harsh conditions when performance is mandatory and there are no exceptions. Their Zeus line of optics lives up to this with a 24/7 mission capable promise. It will perform when you need it to every time without fail. Rain, snow, dust, fog, smoke or whatever else can be thrown at it will have no effect on its performance.
For extras, you are going to get a ton of options of different reticles and even more options for how you see your target. Every possible mode available for a thermal optic is packed into this scope. You can also add a video recorder and extended battery pack if you need them. This is what pure thermal technology has to offer when it is made in one place by one company.
ATN ThOR HD 384
We talked about the ThOR 640 above and this is simply a more affordable version of that optic. The differences between the two are less than you would imagine until it comes to price. If you want to save a fair amount of cash and still get a solid, usable optic this version may be exactly what you are looking for.
The resolution on this optic is about half of the 640 model but the zoom is about half. This is a perfect balance and works out to be a great scope in its own right. If a max of 18x is enough, and it should be, then this scope will perform very well for you. That is a ton of magnification for most any hunting adventure and can be lowered down to almost no magnification for shorter range CQB ops.
There are no differences between this and its big brother when it comes to durability. It can handle all of the same conditions and temperature ranges and will not fog or be damaged from a little water. It can handle the same impacts, all the way up to the largest non-magnum rounds. It is a performer.
Just like with durability, the 384 and 640 have virtually identical extras. Video modes, Wi-Fi, and streaming are all there. It has the same smart rangefinder and ballistic calculator. Seriously, the only differences here that matter are the power. If you are shooting at any normal distance, this should be sufficient for you.
7 FLIR RS32
FLIR has been leading the thermal optics market pretty much since its inception, the technology on most other sights was initially developed by FLIR and adopted by other companies. This has enabled them to lead in thermal optics even if they don’t offer all the extras that most companies do. However, when it comes to state of the art, lightweight thermal scopes you will find none better.
If you are after a thermal scope for AR15 rifles or similarly small platforms, the R-Series by FLIR is your best bet. No thermal optic is truly lightweight but the RS32 at just under 2 pounds is about the best on the market. It is fully waterproof, rugged, shock resistant, and comes with its own internal sealed Lithium battery that carries a 4-hour charge.
Mounted on a standard Picatinny rail, this 5x max optic is one of the best thermal imaging scopes for the money with its multiple pallets and reticle options coupled with a high res detector and target recognition software. The image through this scope, even out to 1000 yards is better than most any other scope in its range.
FLIR has focused more on the optic than the extras with the R-series. It does have video out and can be operated with an external battery pack for those times you plan to hunt for extended periods. The pallet choices are some of the most extensive of any optic and the target alert system works great. Otherwise, it is just a solid, high-quality thermal scope.
8 Armasight Predator
If you are looking for a great thermal scope under 2000 dollars, the predator is by far the best of the best. Just like the R-series, this optic is made by FLIR and no company does the thermal side of thermal optics better. It may lack on the extras but makes up for it on quality.
With a combination of 2x optical and 4x digital zoom, you can get this 640x480 scope up to an 8 power with more range than you would even need to shoot at night. With several different pallets and the latest FLIR technology, this may be the thermal scope with the best longevity ever produced with greater clarity than any other on the market short of actual military hardware.
Like all FLIR optics, the Predator is waterproof, in fact, it is completely submersible, and handles rifle recoil well for most calibers. It even comes with a 3-year warranty should anything happen to it but that’s unlikely. And if the thermal does start to burn out, that particular part has a 10-year replacement.
In addition to the selectable pallets, you also have 5 different reticles to choose from with a repeatable zero system even if you remove it from the rifle. It does have video export and can handle external power for longer hunts. It runs of CR series batteries instead of an internal so you can always carry spares.
Call this the editor’s choice but this is a personal favorite and probably the most amazing thermal rifle scope for the money that has ever been produced.
9 ATN ThOR 4
One of the major issues with thermal optics is the size and bulk. They can be a pain to mount on some older rifles. But ATN, a company best known for high tech options, has given a nod to the classic rifle scope with the ThOR 4 that mounts with standard rings and is compatible with just about any of your older rifles.
The truth is that you won’t find a thermal scope under 1000, this is about as close as you are going to get but you get a hell of a lot with that extra money. Really, for the price, you probably get more from this scope than any other scope on the market.
The resolution is more moderate than many higher end scopes at only 384x288 on the sensor. This limits the extreme ranges but most shots will occur under 200 yards after dark so you should have no worries. The sensor is among the most sensitive on the market so it picks up everything and can display it in the pallet of your choice.
Like all ATN scopes, it records and exports video via an app and has the standard rangefinder. This particular ThOR model has upped the game on the ballistic computer by providing different profiles for different loads and can even factor in angle, temperature, humidity, range, and wind to make sure you are on target every time. All of this and it can run for a solid 18 hours of use. You probably won’t need that unless you are in Alaska in the winter but it's nice to know its there if you need it.
Thermal Scope Accessories
Most thermal scopes are sold as a complete system so very few accessories will be needed. Often you can get by with nothing other than what comes in the box. If you are interested in expanding your use, there are a few products out there, usually offered by the manufacturer, which will improve your overall effectiveness with your thermal optic.
- The number one thermal scope attachment you will need to have is an appropriate mount. Most thermal sights will come with a mount that will work on any of the normal rail patterns. If you are mounting this on a weapon with no rail, you will need to get a small rail mount to attach it to. A few thermal optics have rails separate from the optic. If that is the case with the one you pick, make sure you add a mount.
- Several brands of thermal optic offer an extended power pack. This can be a nice addition if you are planning a night long hunt and want to make sure your scope lasts the duration. Many of these can get you 10+ hours of runtime. If there is no option for a power pack, many thermals charge via micro USB and can be charged with any cell phone power pack.
- If your battery can be removed, some specifically designed batteries for thermal scopes can be purchased from your manufacturer. This can be a great addition.
- You should strongly consider a rain cover for your optic if one is available. Even if your scope is watertight, this is an added layer of protection that will greatly increase the lifespan of gear.
- A final thing that you are going to want to pick up is a cleaning cloth. Those intended for glasses work well or you can get one specifically designed for scopes. Either way, this is a great but that will keep your scope working.
Thermal Scope Brands
While the list above is quite comprehensive to what is available, you should be aware of who the players are as new technology is released every year. Below are the top players when it comes to thermal optics.
FLIR has been around since the late 70s and are the true pioneers of thermal imaging. They may not be the most popular scope or even the most successful but the technology used in EVERY thermal scope is made by FLIR. Other companies may add their own gizmos and gadgets but at the heart, every thermal scope has a FLIR detector.
Though FLIR makes a successful and very high-quality line of riflescopes that is not their primary market. FLIR makes safety equipment, video analytics, night vision, measurement, and diagnostic tools. Most of these are somewhat reliant on thermal imaging.
Most thermal optics used in military and law enforcement application are made by FLIR. They are the first and original.
American Technologies Network (ATN)
ATN is probably the largest producer of thermal scopes but that is far from their only focus. They are best known for their smart optics that pair with other ATN technology to refine distance shooting. They also produce a full line of night vision optics, rangefinders, and many other products for the outdoorsman, hunter, law enforcement, and military.
ATN optics are well known for being the most advanced with a number of additional features and extras found nowhere else. These are highly sought after and considered the gold medal of thermal optics and digital night vision.
While Pulsar has only been around since the late 90s they have found quite the following with hunters. This probably stems from the company being founded by a small group of hunters to do everything they could to enhance the sport. While they are not popular among military or LE, Pulsar remains one of the bestselling brands for hunting.
Compared to the other producers, Pulsar optics are quite affordable. They are used commonly for hog and coyote hunting and have found a small niche recently for deer hunting. Their affordability combined with rock-solid dependability makes them a solid choice for action in the deep woods.
Though very new to thermal optics, Trijicon has been a regular name in the hunting and shooting communities for decades. They optics they produce are known to be nearly indestructible and of the best quality. You can expect many LE and military units that use thermals to move to Trijicon in the future.
Currently, Trijicon only offers 4 models of thermal based on the same platform. All of these are rock solid but expect to pay for them. The quality is top notch, maybe the best out there but this is no different than any of their other products.
Pros and Cons of a Thermal Scope
ProsWith those out of the way, we can get to the good things a thermal scope can do for you.
- Usable in most any lighting condition from bright indoor lights to complete darkness. Because a thermal scope is in no way dependent on visible light, they can be used at any time.
- Most thermal optics have exceptional detection range. The mechanism is very sensitive at detecting heat signatures and often seem them hundreds of yards away.
- A thermal scope can see through atmospheric conditions like dust, rang, fog, and smoke without issue. Likewise, they can see through light foliage and other thin obstruction in many cases. This has made them popular in urban and woodland rescue.
- You can use a thermal to see a target and even to see where a target has been. The residual heat left in tracks and bedding areas will show up on some thermals for a short while after the animal moves on.
- A thermal scope is almost impossible to hide from. Light cover, camouflage, and most other usual tactics are rendered useless. Even handprints will show up on a sensitive unit making hiding and evasion much more difficult.
We are going to start with the bad which is mostly subjective. Likely if you are interested in thermal optics, there is nothing here that will convince you otherwise.
- Cost is the first problem to overcome and it can be a big one. This technology is still relatively rare and new so prices will drop but at this time, there are really no options for an affordable thermal rifle scope.
- Interpreting the image on a thermal scope can be more difficult than some people expect. Without the context of familiar colors and shading, a target at an odd angle or body position can be hard to identify.
- Most thermal scopes are quite large and heavy making them a bit of a struggle depending on the weapon system you are using. This factor has been the largest limitation to their popularity.
- When you can make out a target, getting a positive ID on the target is impossible. An intruder in your home and a family member will look identical.
- Startup/Warm up time on a thermal optic takes some time and battery life is often shorter than desired. This is not a tool that you simply turn on and use. It will take time to get it operational.
Thermal Vs Night Vision
Many people confuse or blend the technologies of thermal optics with night vision, enough so that you will commonly see the term thermal night vision scope. This is a misnomer and does not describe thermal technology well. It is far more than night vision.
Night vision works by reflected light. For traditional night vision that is light in the visible spectrum like from the moon or even stars on very sensitive models. Digital night vision is closer to thermal as it uses IR light but it still needs an IR projector. It picks up the Infrared light that is reflected off a target not what is emanating from it. For this reason, night vision is more properly called light-amplification technology.
Thermal vision uses radiation that is emitted from the target. It doesn’t need any light source to see and can see in complete darkness or the noonday sun. This is not something that either light-amplification technology can do.
How to Zero a Thermal Scope
This is an important point that is often overlooked to the consumer's dismay. You absolutely can not sight in a thermal sight on a standard target. You need special targets that are designed to work with a thermal sight. Even then, it is a challenge because detecting bullet impacts is very difficult at best.
Get an appropriate target and take your time. If you can’t get a thermal target or are having too much trouble with them. Consider placing a halogen light on the ground behind the target shining at the back side. This may be enough to get you by and has worked for me with two separate thermal scopes.
Thermal Scope Hunting Tips
- The first and primary rule of hunting with a thermal scope is to hold your shot. As hunters, we are often excited the first time we get our sights on a critter but don’t rush your shot with a thermal. Target identification can be tricky and no one wants an accident. Make sure you know what you are shooting before you go to the trigger.
- Set up early and give yourself time. Unlike a normal scope, you can’t just turn your optic on and expect to get up and shooting. You need to give the scope time to warm up and calibrate. This can take a few minutes.
- Use a spotter. Most modern thermal scopes will let you stream your view to a tablet or other device. This gives you a second set of eyes to help with spotting and identifying targets. Use this to your advantage.
- Check your local laws. Not all states allow hunting after dark and many that do restrict what can be hunted. Learn your regulations and know your rights before you purchase. Nothing is worse than having an expensive piece of gear that you can’t even use.
There is something very exciting about hunting with night vision. Something that you don’t get in any other form of hunting. There is a feeling of technological superiority, you fell like that advanced hunter in the wild and you know beyond a shadow of a doubt that you own the night.
Anything that approaches you, it's in your sights. You see all. Night vision is a great technology but nothing in the world beats thermal!