10 Best Thermal Monoculars to Buy in 2021 [Reviews & Guide]

Best-Thermal-Monoculars

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In case you are planning to buy a thermal vision monocular, you’re in the right place. We will share reviews of the top models in the market along with an elaborate buying guide to help you make the best choice.

What about the technical details that a first-time buyer should know about? 

No worries. We will cover that too.

In general, handheld thermal monoculars are very effective for hunting or animal spotting during the night or in dark conditions.

The point is, picking the best thermal monocular needs substantial investment. So we recommend that you choose the device after some consideration.

So let’s start the journey.

Contents

In a Hurry? Here are Our Top 3 Best Thermal Monocular Options

Best value
Pulsar Axion Key XM30 2.4-9.6x24 Thermal Monocular Black,...
Best Overall
ATN OTS-HD 640 5-50x, 640x480, 100 mm, Thermal Monocular...
Best Price
FLIR Scout TK Handheld Thermal Imaging Monocular
Pulsar Axion Key XM30 2.4-9.6x24 Thermal Monocular Black,...
ATN OTS-HD 640 5-50x, 640x480, 100 mm, Thermal Monocular...
FLIR Scout TK Handheld Thermal Imaging Monocular
  • 320×240 Sensor
  • 1,300-yard Detection
  • IPX7 waterproof
  • 320×240 Sensor
  • 1,300-yard Detection
  • IPX7 waterproof
  • 320×240 Sensor
  • 1,300-yard Detection
  • IPX7 waterproof
-
-
-
Best value
Pulsar Axion Key XM30 2.4-9.6x24 Thermal Monocular Black,...
Pulsar Axion Key XM30 2.4-9.6x24 Thermal Monocular Black,...
  • 320×240 Sensor
  • 1,300-yard Detection
  • IPX7 waterproof
-
Best Overall
ATN OTS-HD 640 5-50x, 640x480, 100 mm, Thermal Monocular...
ATN OTS-HD 640 5-50x, 640x480, 100 mm, Thermal Monocular...
  • 320×240 Sensor
  • 1,300-yard Detection
  • IPX7 waterproof
-
Best Price
FLIR Scout TK Handheld Thermal Imaging Monocular
FLIR Scout TK Handheld Thermal Imaging Monocular
  • 320×240 Sensor
  • 1,300-yard Detection
  • IPX7 waterproof
-

How thermal imaging works

Thermal monoculars are devices that detect very minute differences in the heat signature from an object. 

Basically, the process involves detecting the heat signatures using thermal imaging technology.

Here’s how it functions.

All objects radiate heat in the form of infrared light. A thermal imaging monocular uses an infrared sensor to detect these wavelengths. 

The thermal image formed by the sensor is also called a thermogram. It captures the temperature gradient of any object. Then each temperature is differentiated by a shade of a color. The colors make it easier to differentiate between hotter and colder temperatures.

In addition, they also contain a normal lens that captures the visual image. In the end, these two images are superimposed to generate a detailed thermal image on the screen.

This technology is used in heat vision cameras or thermographic cameras used by the police and military.

thermal monocular test
The image was taken on Sept. 9, 2013, Alaska when Army Spc. Nicholas Kuefler tests mini thermal monocular, night vision optic lenses before a combat training parachute insertion on Joint Base Elmendorf-Richardson. (Source)

Usually, a thermal monocular can sense the heat radiations at the range of -50°C to 2000°C.

And guess what?

That makes thermal monoculars very useful in firefighting. Firefighters use it to check if any injured persons are lying beneath the debris, doors, or damaged walls. This can lead to the faster rescue of the injured.

Also, they are very effective to protect farms from wild hogs and boars at night. 

Moreover, thermal monoculars are extensively used in military, surveillance, and energy analysis, Other fields of use include satellite imaging, weather reporting, and various search and rescue operations.

Table: Best 10 Thermal Monoculars of 2021

PRODUCTPRODUCT NAMEKEY FEATUREOUR RATING
ATN-OTS-HD-640-Thermal-Smart-HD-MonocularsATN OTS- Thermal Smart HD 640 Monoculars3D Gyroscope5/5
Pulsar-Helion-XP-Thermal-MonocularPulsar Helion XP Thermal MonocularStream Vision App4.9/5
ATN-OTS-HD-384-Thermal-Smart-HD-MonocularsATN OTS-HD 384 Thermal Smart HD MonocularsE-Zooming4.9/5
pulsar-axion-xm30-monocularPulsar Axion Key XM30 Monoculars1,300 yard Detection4.8/5
FLIR-Scout-TK-Pocket-Sized-Thermal-MonocularFLIR Scout TK Pocket-Sized Thermal MonocularQuick User Controls4.8/5
FLIR-Breach-PTQ136-Thermal-Imaging-MonocularFLIR Breach PTQ136 Thermal Imaging MonocularWeigh 210 g4.7/5
Leupold-LTO-Tracker-ThermalLeupold LTO Tracker Thermal Monocular6X Zoom4.7/5
bestguarder-hd-digital-nv-monocularBest Guarder Digital Night Vision MonocularIn-built Microphone4.7/5
Armasight-Spark-Night-Vision-MonocularArmasight Multi-Purpose Spark Thermal MonocularDouble Resolution4.6/5
Scout-III-240-Thermal-ImagerFLIR Scout III-240 Thermal Imaging Monocular350 m Detection4.5/5

Best Thermal Monoculars: 10 Monoculars Reviewed

Here are our reviews of the best Thermal monoculars from the top popular brands and their ranking.

1. ATN OTS – Thermal Smart HD 640 Monoculars

ATN OTS – Thermal Smart HD 640 Monocular is a fantastic and high-quality monocular that has the highest recommendations from the hunters and wildlife enthusiasts.

Its thermal sensor has a high-level resolution of 640 x 480 pixels which is the pixel rating of standard television.

ATN-OTS-HD-640-Thermal-Smart-HD-Monoculars

Specifications

  • Brand: ATN
  • 320×240 Sensor
  • 1,300-yard Detection
  • IPX7 waterproof
  • 640*480 pixel HD resolution
  • Weighs 1.85 pounds

The ATN OTS Thermal Smart HD 640 Monocular is a fantastic and high-quality monocular that has the highest recommendations from hunters and wildlife enthusiasts.

Its thermal sensor has a high-level resolution of 640 x 480 pixels which is the pixel rating of standard television.The eminent thermal sensor used in this ATN OTS Thermal Smart Monocular can detect even a minute temperature change. The additional features like 3D gyroscope and E-compass allow you to see in complete darkness.

user about atn ots hd thermal monocular
A shooter used ATN OTS HD thermal monocular to sight his coyote prey and got a perfect shot.

Moreover, the ATN OTS Thermal Smart Monocular can provide soft and delicate zooming by the simple pressing of a button.

If you want videos and photos with the best resolution, this is a great piece of gear.

Also, with the upgraded Wi-Fi module in this product, you can share the adventures in a few simple steps.

The inbuilt rangefinder detects the target really fast. There is an SD card for image storage.

Want to add geographical information to the images? The device also comes with the geotagging feature.

The weight of just 1.85 pounds and the compact dimensions make this an easy unit to carry around with you.

Read our full review of ATN OTS-HD 640 Thermal Monocular here.

Below, we have added the comments and feedback from hunters or viewers who used the ATN OTS HD 640 Thermal Monocular.

A feedback of an OTS user on Reddit.atn ots 640 reddit

Pros

  • High-quality features
  • Affordable price
  • A hi-tech processor
  • 3-D Gyroscope
  • Simple interface

Cons

  • No mounting options
  • Gets scratched easily

2. Pulsar Helion XP Thermal Monocular

Pulsar Helion XP Thermal Monocular is a highly recommended monocular for hunting and outdoor sports as it has advanced thermal features.

This thermal monocular is designed with a large and powerful 50mm lens. The magnification range for this Pulsar monocular is from 2.5x to 20x with the smooth zoom feature which means you will get the high-quality thermal images.

Pulsar-Helion-XP-Thermal-Monocular

Specifications

  • Brand: Pulsar
  • A resolution of 640 x 480 pixels
  • 50Hz refresh rate
  • High-resolution AMOLED display
  • IPX7 waterproof
  • A range of 2000 yards

The Pulsar Helion XP Thermal Monocular is a highly recommended monocular for hunting and outdoor sports.

This thermal monocular is designed with a large and powerful 50mm lens. The magnification range for this Pulsar monocular is from 2.5x to 20x along with smooth zooming. 

The resolution of a thermal sensor in this thermal monocular is about 640×480 pixels. The Helion XP possesses the uncooled micro-bolometric matrix (640X480) at 17 µm.  So you’ll get high-quality thermal images.

user about pulsar thermal monocular
A hunter shared his experience of using a Pulsar thermal monocular for hunting hog.

This Helion XP monocular has a built-in video recording option. So capturing the images and video is effortless. 

Point to be noted- it comes with 8GB of internal memory for storage.

Here is the best part…

This Helion XP thermal imaging monocular/scope can detect the heat signatures of an object up to 1800 meters away. That makes it ideal for hunting trips.

The superb display and a refresh rate of 50Hz ensure excellent image quality even when you are in motion. 

The batteries last for more than 7 hours. A very good performance that’s ideal for long field trips.

Pulsar-Helion-XP-Thermal-note

Pros

  • Bright and clear image
  • Long detection range
  • Lightweight
  • Good battery life

Cons

  • High price
  • A narrow field of view

3. ATN OTS-HD 384 Thermal Smart HD Monoculars

The ATN OTS-HD 384 Thermal Smart HD monocular is the best choice for mountaineers and hikers. This device combines the thermal imaging abilities with the High Definition view. The advanced features in this monocular reduce the guessing and providing accurate data while hunting.

ATN-OTS-HD-384-Thermal-Smart-HD-Monoculars

Specifications

  • Brand: ATN
  • A resolution of 384 x 288 pixels
  • 3D Gyroscope and E-compass
  • Smart rangefinder
  • Wi-Fi streaming

The ATN OTS-HD 384 Thermal Smart HD monocular is the best choice for mountaineers and hunters. This device combines thermal imaging abilities with an HD view. The advanced features provide accurate data while hunting through a user-friendly interface.

Check this out: The monocular has an OTS-HD Obsidian core processor. It delivers a fast and lag-free performance through cutting edge technology.

Also, the OTS-HD monocular has a built-in smart rangefinder which helps to measure the distances accurately. In most cases, it makes ranging a target simple and accurate.

The 3D gyroscope in this monocular is one of its best features. It delivers sharp images even when you’re on the move.

ATN-OTS-HD-384-note

Next, you can use the E-Zoom feature to narrow your focus on the target. You’ll also find the zooming process to be super smooth.

This ATN OTS HD 384 thermal monocular has advanced connectivity features like Bluetooth and Wi-fi. It can also be connected with a smartphone or tablet through the dedicated ATN Obsidian mobile app.

Lastly, there is also a GPS antenna for geotagging your images and videos.

To sum it up, this is one of the most affordable monoculars for supporting your next expedition.

Read the detailed review of the ATN OTS HD 384 monocular here.

Pros

  • Built-in rangefinder
  • Smooth zooming
  • Wi-Fi compatibility
  • Good battery life

Cons

  • Controls take time to learn
  • The range is short

4. Pulsar Axion Key XM30 2.4-9.6×24 Thermal Monocular

pulsar-axion-xm30-monocular

Specifications

  • Brand: Pulsar
  • Resolution of 320 x 240 pixels
  • 4x digital zoom
  • 1300 yard detection range
  • IPX7 waterproof rating
  • HD AMOLED microdisplay 

The Pulsar Axion model is another fantastic thermal vision scope from Pulsar. Like XP and Quantum series, the Axion series also has a few good models. We chose Axion Key XM30 from the series to review here.

The Pulsar XM30 is a high-end thermal monocular, mainly designed for hunting. It has an excellent detection range of 1,300 yards. 

Coming to the built quality, it’s made of lightweight but durable Magnesium alloy to ensure rigidity.

With this hunting monocular, you can view in varying conditions using its eight color palettes. There are five modes- White Hot, Hot Black, Red Hot, Rainbow, and Ultramarine.

The Axion has a high magnification range of 2.5x-10x in its optics. In addition, you get 4x digital zoom, continuous zoom, and picture-in-picture zoom.

Pulsar Axion Key XM30 monocular does not have Stream Vision Compatibility, and also it has less magnification in its class.

The monocular has a very compact size that can easily fit in your palm or in a standard jacket pocket. The excellent portability makes it a perfect tool for spotting and scouting.

With a 16 GB internal memory storage of videos and photos won’t be a problem. There is also support for the Stream Vision app.

For entry-level users, this is one of the most value for money choices in the market.

Pros

  • Rugged design
  • Excellent display
  • 16 GB internal memory
  • Weatherproof built

Cons

  • Not the best choice in freezing winters

5. FLIR Scout TK Pocket-Sized Thermal Monocular

Honestly, the FLIR Scout series has some of the best thermal monoculars for the money. 

FLIR Scout TK is the compact handheld thermal monocular that’s easy to use, pocket-sized, and perfect for targeting animals.

Thermal imaging technology used in this monocular includes microbolometers.  They deliver a top-notch performance while minimizing power consumption and reducing weight.

FLIR-Scout-TK-Pocket-Sized-Thermal-Monocular

Specifications

  • Brand: FLIR
  • A resolution of 160 x 120 pixels
  • VOx Microbolometer detector
  • Display: 640 X 480
  • 20°×16° FOV
  • 100 yards detection range

Admittedly, this isn’t a top-grade high-resolution sensor. But, as an entry-level thermal imaging monocular the quality offered is commendable.

The frame rate of this monocular is 9 frames per second. That’s a decent value for an entry-level thermal vision monocular. 

Also, the 640 x 480 LCD display offers good clarity and brightness levels. The field of view of 20×16 degrees makes it good enough for outdoor use.

What about the dimensions?

With a size of 6.0″ x 2″ x 2″ and a weight of 6 oz, it’s one of the lightest models you’ll find.

The FLIR Scout TK thermal imager/monocular has a great intuitive user-interface. There are four easy buttons to control the device.

FLIR-Scout-TK-thermal-note

In addition, the device has different color palettes and allows you to choose as per your likes. 

The rechargeable Lithium-Ion battery used to power the monocular which can long up to five hours of processing time.

Read the complete review of FLIR Scout TK Thermal Monocular here.

Pros

  • Easy to use
  • An affordable price
  • Lightweight and compact
  • Fast startup time

Cons

  • A low refresh rate
  • The range is short

6. FLIR Breach PTQ136 Thermal Imaging Monocular

The FLIR Breach PTQ136 is a multi-purpose monocular that can be used in varying light conditions. This device is primarily designed for law enforcement but is equally useful in home inspections and as day/night hunting gear.

FLIR-Breach-PTQ136-Thermal-Imaging-Monocular

Specifications

  • Brand: FLIR
  • A resolution of 320 x 256 pixels
  • 1280 x 960 FLCOS display
  • A 24° x 19° FOV
  • 60Hz refresh rate
  • 205-meter detection range

Coming to the features, the FLIR PTQ136 has a 12µm Boson core which is only 7 ounces and has a compact design.  

The 320 × 256 VOx Microbolometer does a great job of picking up heat signatures. As a result, you get excellent thermal sensitivity that produces sharp and clear images at all times.

Moreover, the total weight of this device is 210 grams. So carrying it in your hand or pocket for long hours isn’t an issue. The rugged design also makes it resistant to drops and shocks.

The 16 mm of eye-relief is good but not the best.

Now, this device also allows hands-free use.

flir breach ptq136 compact size
The image shows how compact FLIR Breach PTQ136 monocular is that it is just the size of his palm.

There is the mounting rail on the right side of the FLIR PTQ136. Using this, you can attach the device to any firearm or helmet. With a weight of 210 g, it’s also on the lighter side.

Flir mentions 90 minutes of battery life with the CR123A 3V Lithium battery. We feel that’s on the lesser side.

Here is the detailed review of the FLIR PTQ136 thermal monocular.

FLIR-PTQ136-note

Pros

  • Good image quality
  • High refresh rate
  • Lightweight and compact
  • Easy to operate

Cons

  • Low battery life

7. Leupold LTO Tracker Thermal Monocular

Leupold LTO Tracker thermal monocular is a thermal imaging mini system that very much resembles a small torch. The aluminum built and low weight of 1 pound makes this a handy device for outdoor use.

Leupold-LTO-Tracker-Thermal

Specs

  • Brand: Leupold
  • Sensor Resolution of 320×240
  • Amoled display with a resolution of 390 x 390 pixels
  • Range of 750 yards
  • 6x digital zoom

Note, there is also a Gorilla Glass cover over the circular display.

In fact, this Leupold LTO Tracker Thermal Monocular is not only easy to use, but it’s also one of the best durable and waterproof monoculars.

The 390 x 390 resolution display isn’t large but offers great clarity and contrast. So, spotting objects even in total darkness isn’t an issue. The 6x digital zoom is also a useful feature in outdoor scenarios.

Leupold-LTO-Tracker-Thermal-note

The high-quality infrared sensor delivers good quality images even at the long end of the optical range.

On top of that, you get eight color palettes to customize the display as you need.

But beware. This thermal vision monocular isn’t designed to withstand recoil from firearms.

Here is a video shared by a Leupold LTO Tracker user who viewed people and things around them through this thermal viewer.

Read the full review of Leupold LTO HD Thermal Imaging Tracker.

Tip:- Here we’ve compared the best monoculars from Leupold & FLIR (Leupold LTO Tracker VS FLIR Scout TK).

Pros

  • Multiple color palettes
  • Simple controls
  • Long battery life
  • Small and lightweight

Cons

  • The range is short

8. Bestguarder Digital Night Vision Monocular

The Bestguarder Digital Night Vision Monocular is a top-notch thermal monocular with multiple attractive features. We think it’s one of the best thermal monoculars for hunting you can pick.

Bestguarder-HD-Digital-Night-Vision-Monocular

Specifications

  • Brand: Bestguarder
  • 5 MP CMOS sensor
  • 1.5 inch TFT screen
  • Built-in 850Nm infrared illuminator
  • Range of 350 meters
  • IPX4 water resistance

We think it’s a good choice To start with, this is a thermal imaging monocular that allows you to capture high-quality HD photos and videos.

Photographs can be easily snapped at various resolutions including 2592 x 1944, 1600 x 1200, 640 x 480. Videos of 1280 x 720 and 640 x 480 can be recorded at a rate of 30 frames per second. 

Bestguarder-Digital-Night-Vision-note

This monocular also has an inbuilt IR illuminator to provide extra clear night vision. The viewing range of this monocular is 350 meters. This is supported with a 6x magnification.

The device also comes with an in-built microphone to capture sounds. You can also connect it with your laptop or smartphone for live streaming.

The addition of two threaded 1/4″-20 tripod mount holes allow you to set it up easily.

On the whole, this is a versatile device that offers great value. Be it hunting, night-time fishing, bird watching, caving, or surveillance, the device offers reliable performance.

Take a look at a complete review of the Bestguarder WG-50 Digital NV Monocular here.

Pros

  • Effective digital zoom
  • Value for money
  • Adjustable eyepiece
  • User-friendly interface

Cons

  • No autofocus

9. Armasight Multi-Purpose Spark Thermal Monocular

Now, at a first glance, this device looks pretty much similar to an ordinary video camera. 

But make no mistake. 

The Armasight Multi-Purpose Spark thermal monocular is an advanced device that comes with CORE technology. What’s that?

Armasight-Spark-Night-Vision-Monocular

Specifications

  • Brand: Armasight
  • A resolution of 60-70 lp/mm
  • Enhanced CORE technology
  • Built-in Infrared illuminator
  • 35° FOV
  • 20mm eye relief
  • Water-resistant design

Well, it uses tubes that are made from ceramic compounds fused with special metal alloys for the best performance.

It also offers dynamic sensitivity to provide double-resolution up to 70 lp/mm (lines per millimeter). This technically means 35 white lines and 35 black lines can be drawn in one millimeter.

There is also a built-in Infrared illuminator for better image clarity at low light.

In addition, there is a 3x zoom along with a generous 20 mm eye relief. The ergonomic design also ensures that it’s easy to use.

Armasight-CORE-IIT-note

You can use it with either a CR-123 3V or a CR123rechargeable battery. The battery life is excellent- close to 40 hours.

Keep in mind that the device is water and fog-resistant but not fully waterproof. So it’s not for use near water bodies or in the rainy season.

One more thing…

We’d like to inform you this particular product is unavailable right now. Whenever it comes back to the market, we will provide intimations from our end.

Pros

  • Good optical clarity
  • Ergonomic design
  • Long battery life
  • 2 years of warranty

Cons

  • The infrared illuminator could be better
  • Focusing can be tricky

10. FLIR Scout III-240 Thermal Imaging Monocular

If you are looking for superb image resolution, the Pulsar Lite Quantum Thermal Monocular is a good pick.  Apart from the  384 x 288 pixels, it also comes with a 17um (0.017 millimeter) pixel pitch core for better image clarity. 

Scout-III-240-Thermal-Imager

Specifications

  • Brand: FLIR
  • A resolution of 384×288 
  • 640×480 AMOLED display
  • 50Hz refresh rate 
  • A visual range of 875 yards

Basically, that’s the exact distance from the center of one pixel to the other.

Moreover, the high 50hz refresh rate makes it a good pick for capturing images while in motion.

But that’s not all…

The Pulsar Quantum monocular can be calibrated in automatic, semi-automatic, and also in manual mode. In addition, it’s supported by the stadia metric rangefinder to measure exact distances.

The high-resolution screen uses the active-matrix organic light-emitting diode technology. The image delivery is crisp and doesn’t require backlighting like an ordinary LED screen.

Note that it has seven different color viewing modes apart from the monochrome mode.

FLIR-Scout-III-240-note

Here’s something interesting.

The device has a camouflage mode that turns the display off while all other systems keep working. 

Lastly, the device can also be connected with an external power supply by using a special jack. A useful feature if you need a longer operating time.

Check the complete review of FLIR Scout III 240 Thermal viewer here.

11. Pulsar Lite Quantum Thermal Monocular

Pulsar Lite Quantum Thermal Monocular is one of the stylish and muscular monoculars which provides a sound grip to the user and also provides a crystal clear screen with a high definite resolution of 384 x 288 pixels, moreover the refresh rate is satisfactory to 50 Hz.

Pulsar-Quantum-Lite-Thermal-Monocular

Specifications

  • Brand: Pulsar
  • Resolution: 384 X 288
  • Display: 640 X 480
  • Frame rate: 50 Hz

Different Modes

This innovative pulsar quantum monocular can be calibrated in automatic mode, the semi-automatic mode and also in manual mode which is also supported with the stadia metric rangefinder in which distances are measured with the telescopic instrument to find the exact distance of your counter agent from the monocular.

High Resolution

Pulsar Lite Quantum Thermal Monocular proves to be more lucid in providing smooth and crisp thermal images on a high-resolution screen with the 640 x 480 pixels through the active-matrix organic light-emitting diode technology which is a thin film technology containing electroluminescent organic compounds which require no backlight like an ordinary LED screen.

Micrometer

The clarity is great not only because of the pixel rating but also due to the pixel pitch ratio which is as small as 17 micrometers (0.017 millimeter), which is exactly the distance from the center of one pixel to the other.

Pulsar-Lite-Quantum-note

Added Features

This monocular can visualize the thermal images even beyond 275 yards which also has seven different color viewing modes apart from the monochrome mode and also this robust monocular switches off automatically when not in use thus saving the power.

Not only that, this product works on both hot white and hot black mode and weighs around 1.9 pounds with the dimensions of 6 x 10.5 x 4.5 inches.

The hand straps associated with this monocular prevents the accidental damage of the device and this Pulsar Lite Quantum Thermal Monocular is powered by 4 AA batteries which are also equipped with the adaptable power supply.

Did you know?

Thermal imaging is being used to minimize the spread of Coronavirus (COVID-19) by detecting body temperatures.

Yes. Infrared thermography is able to detect the elevated body temperature that may be due to a viral infection.

In fact, IR radiation is a safe diagnostic tool to safely inspect people while minimizing viral transmissions. it’s an effective way to curb the spread of diseases like COVID-19, SARS, and other infections.

thermal scanning for covid 19
In Delhi Airport, they use thermal scanners to check the passengers for COVID-19.

Initially, public health ministries were looking for a reliable, easy, fast, and contactless method to detect and contain COVID infections.

Thermal detection emerged as a perfect solution.

Now, it’s widely used around the world in all the public places and transport areas to detect elevated body temperature.

Important Things to Know Before Choosing the Thermal Imaging Monocular or Thermal Viewer

What is a Heat Signature?

Every object in the world emits radiations with various wavelengths.  However, these radiations differ from each other.

Humans and certain animals emit radiation in the range of 0.75 to 1000 microns. This is very much similar to the wavelengths of the infrared radiations aka infrared signature.

This heat radiation from each object is called the heat signature.

Needless to say, infrared radiation cannot be seen by the naked eye because of the ocular limitations of the human eye.

Difference between Thermal and Night Vision Monocular

Basically, both thermal imaging and Night Vision are used for viewing in the darkness and unclear weather conditions. But they are two different technologies.

thermal vs night vision monocular
Thermal Imaging Monocular VS Night Vision Monocular

Thermal Imaging Monoculars

Thermal imaging technology relies on the heat signature. This is nothing but the emitted Infrared (thermal) energy from humans, animals, and any other object.

In reality, the emitted energy rate differs with every object. 

The IR radiations from various objects are captured by the sensitive thermal imaging sensor of the monocular. The elements inside the sensor create a thermogram, i.e. a precise temperature pattern. To form an image, this is converted into electrical impulses

The images produced by these monoculars usually are grayscale in nature. The object which emits a good amount of heat appears to be white on the screen while the cold objects appear to be black.

Many monoculars use a color palette where colder temperatures are marked by shades of purple, blue, or green. The higher temperatures are assigned a shade of red, orange, or yellow.

Night Vision Monocular

On the other hand, Night Vision Devices (NVDs) work based on amplifying the available light and ambient light to provide night vision.

These are often called Star/Moon devices as they use the light from star and moon to provide better viewing at night.

Night vision devices fail to work when it’s cloudy or there’s no light. In such scenarios, thermal devices are a more reliable choice.

Types of Thermal Monoculars

There are many types of thermal imaging monoculars available. These are broadly categorized into two types based on the way they are being used.

» Handheld thermal monocular» Head-mounted thermal monocular

Thermal Handheld Monocular

Thermal Handheld Monocular is the most commonly used type and very popular among the hunters and wildlife observers.

handheld-monoculars

Basically, these thermal devices are compact and rugged enough to carry around your work field.

Most of the handheld monoculars are lightweight for easy carry.

When compared to other types, these handheld devices are cost-effective and have a long work life.

Now, let us come to the downsides of handheld monoculars.

Using a handheld monocular for an extended time can be tiring. Imagine that you need to run or move fast with a monocular in your pocket or around your neck.

Sounds familiar?

In such cases, you need to be careful about your device. So chances are there you’ll lose your focus on the game.

Prolonged use of monoculars can also lead to eye fatigue as they aren’t the best choice for relaxed viewing.

Lastly, if you’re looking for a wide “field of view”, the thermal monocular is not the best choice.

Thermal Head Mount Monocular

headmount-monocular

Another major type of thermal imaging monocular is head-mounted devices. As you can realize, these monoculars are used as mounting on the helmet or headgears.

The most important point is…

You don’t have to hold this device as it’s a hands-free operation. 

With these devices you can use your hands for other activities like climbing, using a rifle or weapon, or any other physical activity.

The right attachment of a helmet with a mounted monocular offers better stability. So you’ll get a clear thermal image.

Unlike handheld monoculars, you can use head-mounted devices for longer periods. 

You can simply stand or sit in a place and continuously monitor the target areas or surfaces. Moving around with these devices is also much easier.

The main drawback of this head-mounting device is its price range. These devices are priced higher than handheld devices.

Difference between Monocular and Spotting Scope

Both devices are essential gear for outdoor activities like hunting, climbing, camping, etc. They may look the same but have unique features and working procedures.

monocular vs scope
Monocular Versus Spotting Scope

No wonder most of the time buyers are confused between monocular and scope.

Let’s look into the difference between monocular and scope to see how they differ.

What Is a Monocular?

The monocular is much similar to binocular. it’s a portable and compact tool that can be used as a magnifying glass by hunters or campers.

In a way, we can consider it as a half barrel of a binocular. So the user has to see through one eye using this device.

The name monocular is a combination of two words-  “Mono”, which means ‘One’ in Greek, and “Oculus” which means ‘Eye’ in Latin.

Thermal monoculars are handy optic devices to have. Moreover, they are also available with advanced features like a built-in compass, rangefinder, and effective zooming power.

That makes them a complete tool for outdoor adventures.

What Is a Spotting Scope?

We have already said monocular is similar to binocular. Likewise, the spotting scope is much similar to the telescope. This makes them effective tools for hunters.

Spotting scopes offer high-powered optics with large apertures. The features of this device allow seeing small animals like birds, deer, hogs, etc from a long distance.

Basically, the magnifying powers of a spotting scope start where a traditional binocular leaves off. They can be based on a prism or a combination of lenses or mirrors.

Let’s look into the advantages and disadvantages of Thermal monocular and Spotting Scope.

compare
Advantages
advantages of spotting scope and monocular
Disadvantages
disadvantages of spotting scope and monocular

Monocular Vs Spotting Scope: Which is better?

In reality, thermal monoculars and spotting scopes are completely different devices. 

Monoculars are lightweight and portable hunting or viewing devices. On the other hand, scopes are heavyweight but provide thermal images from higher distances.

In Hunting

With a highly portable structure, monoculars are a good choice for hunting. But hiding from your prey is a major point that you need to ensure while using a screen in the dark.

The monoculars are basically lower powered than the spotting scopes so these aren’t the best option over very long distances.

Spotting scopes offer a high detection range of hundred yards and more, so you can closely monitor your prey from a safe distance

Ideally, a small size low-powered spotting scope can be the perfect choice for professional hunting. But only if you aren’t worried about the weight and tripod setting,

Otherwise, compact and easy-to-carry monoculars are good enough to start with.

hunt

In Birding

Birding or Birdwatching is the form of wild observation in which the rare birds are observed or recorded. It can be done by the naked eye or using any visualization tools like binocular, monocular, scopes, and cameras.

A spotting scope will provide clear images of birds’ feathered bodies and activities. Scopes also come in angled and straight versions. That gives you the chance to choose as per your preference.

But setting up the tripod and changing it for every new spot will be time-consuming.

In such cases, monoculars win the race. You can hold the device in your hands or mount it in headgear. It’s a practical choice for catching the actions of the birds instantly. 

bird-watching

In Astronomy

You can see some соnѕtеllаtіоnѕ using a monocular but there is no big difference than seeing the same with the naked eye. Monoculars are too low-powered to see that far.

By contrast, spotting scopes are cheaper alternatives to the telescope.

Now, you may wonder why.

The fact is, for proper observation of the night sky, a minimum magnification of at least 60x is necessary.

The maximum magnification range of most of the monoculars is just 10x.   But the minimum magnification range of best thermal scopes usually starts with 20x and it can provide the zoom as close as to 100x.

However, to get the best quality lens and the best glass coating in a scope, you’ll need to spend considerably more.

astronomy

Thermal Monoculars – Buying Guide

So you have decided to buy a thermal monocular. But what are the factors that a quality thermal monocular should have?

Good question.

Here’s our guide that will help you to choose the best thermal imaging monocular from the crowded market.

Durability

The durability of any device is the first and foremost factor that you need to consider. More so as a thermal monocular is mostly for outdoor use.

Naturally, a thermal monocular is subjected to stress, pressure, and climatic changes. So it should come with robust construction and waterproof features.

It should also be able to function effectively within a relatively large temperature range.

The truth is, monoculars with poor durability will come cheap but won’t serve your cause.

When maintained well, a thermal monocular can last for a decade. So make sure that the product comes with a solid warranty.

Magnifying factor

The magnifying factor is determined by the ratio between the image distance and the object distance. Monoculars should be able to provide proper imaging even when the object is several hundreds of yards away.

Usually, magnification is specified with two numerals like 10 x 18. Here, the first digit (10) means that it magnifies the image 10 times larger than normal. The second digit’s about the diameter of the lens in millimeters (in our case it’s an 18 mm lens).

Keep in mind that higher magnification levels amplify any lens movement. So moving anything more than 10x magnification will need an image stabilizer or a tripod.

Moreover, higher magnification will also narrow down the field of view.

The Refresh Rate

This is the frequency at which the screen image is refreshed. it’s measured by ‘Hertz’.

The common refresh rates found in monoculars are 9Hz, 30Hz, 50Hz, and 60Hz. The higher the value, the faster is the refresh rate. Slower refresh rates can cause image blurring for a fast-moving object.

For professional use related to hunting or wildlife watching a refresh rate of 30Hz or more is the best choice. Higher refresh rates also make the image appear smoother on the screen.

​​Resolution

The resolution determines the clarity of an image. Clarity is based on the number of pixels in that image.

Basically, pixels are small squares that collectively build the image.

Allow me to explain.

Fetch a hand full of yeast and draw your initial with it.

Repeat the same with some white mustard. Of course, the one with the mustard will be more clear and vivid to the eyes. 

Why does this happen?

It’s because the number of mustards is definitely more compared to the number of yeasts.

This is the same as how the pixels operate.

Usually, the resolution is specified with two numbers; like 2000 x 1000. This means there are 2000000 pixels (or 2 Megapixels) in the image.

So it’s necessary to check the number of pixels in the thermal sensor in your monocular while purchasing it. Ideally, 480 x 640 pixels is the minimum standard that you need to pick.

Power

Whatever may be the features in a monocular, without the proper power source it’s totally useless.

Imagine a monocular running out of time in the critical phase of a hunting expedition. Annoying, isn’t it?

Point to be noted- Wi-Fi and Bluetooth connectivity can drain the battery faster. So make sure that you pick a device that offers a battery life good enough for your purpose.

Anywhere around 7 to 10 hours of battery life is good enough for most purposes.

Handy and recordable

A thermal monocular should be light and compact for easy carrying. This also makes sure that you can operate it with ease.

In addition, you can easily stuff them inside the backpack or a pocket when needed.

A few monoculars can be supported with tripods that are tightened with screws. Now that’s a great way to get clear and stable images. However, you have the extra burden of carrying a tripod and setting it up for use.

Advanced Features

Some of the additional and smart features offered by the thermal imaging monoculars are as follows.

Thermal Monocular with Rangefinder

Nowadays, almost all thermal monoculars and thermal scopes from popular brands have a built-in rangefinder. This rangefinder makes the hunter’s life easy by eliminating the need for guesswork.

The rangefinder displays the accurate distance between you and the object on the screen. In most cases, the smart range finder starts the range calculation automatically.

Thermal Monocular with Wi-fi

Thermal monocular with Wi-Fi features allow their users to connect to smartphones or tablets. This makes it possible to view the images on these devices.

In addition, you can also share the files from your gallery with your friends in real-time. Some of the thermal monoculars also allow live Wi-Fi video streaming on YouTube.

Thermal Monocular with Built-in Compass

The built-in compass in the device provides the angle observations. This makes it easy for users who are out in the wilderness.

The reading of the compass is from 0 to 360 degrees. The meaning of readings is determined as under:

» 360°: North Direction

» 270°: West Direction

» 180°: South Direction

» 90°: East Direction

If the reading is 100°, it means 10 degrees east to south.

Thermal Monocular with Smooth Zoom

Apart from a fixed zoom, recent thermal monoculars have been equipped with Smooth Zoom. This provides you sensitive ultra-slow zooming that’s easy to use.

This is a great feature to identify the target from a close range. A variable magnification anywhere between 2x to 4x will be effective for practical use.

So these are the main factors that you need to check before picking the best thermal monoculars. Make sure you go through all these factors before investing.

Applications of Thermal Monocular

Thermal imaging monoculars are mostly used in military, law enforcement, hunting, and wildlife observations.

Thermal Monocular for Hunting

In hunting, thermal monoculars offer a clear view of the target from long distances.

In addition, most of the advanced monoculars are designed with a range finder and enhanced magnification.

This means you can stay away from any attacking animal and hunt safely.

Thermal monoculars are widely used for hunting deer, hog, and coyote.

Above video demonstrating how FLIR Scout TK Pocket-Sized Thermal Monocular shows the thermal imaging while deer hunting.

Thermal Monocular for Military

Thermal monoculars used for the military have a rugged and strong construction. So the devices are weatherproof, dustproof, and impact-resistant, to face more tactical and tough situations

There are a few brands that have designed the tools specifically for military and security use. 

MH Technology Group is one of the leading manufacturers developing Night vision optics and Thermal gears for the Military.

The above video is explaining the features of the M670 Military Thermal Monocular from MH.

Thermal Monocular for Law Enforcement

Thermal imaging devices for law enforcement help the cops or security officials in special situations.  This can involve locating the criminals who are hiding in buildings or construction by detecting infrared thermal energy or radiation.

Since these thermal monoculars come as lightweight, portable, and are one-hand operated, they are easy to carry for long hours.

The attached video of FLIR Thermosight Pro PTS736 shows how it detects the hidden thief using thermal imaging.

Frequently Asked Questions

u003cstrongu003eHow law enforcement use this thermal technology?u003c/strongu003e

These devices are useful in various ways for law enforcement. Thermal imaging devices help the police officers to stay safe while searching or trapping the criminals who are hiding in a building or dark places.u003cbru003eThermal devices can also be used to identify a recently running car by detecting the heat signature of the engine. These features are also used to collect the evidence from the crime spot that can help to find the suspects.

u003cstrongu003eCan thermal imaging see through clothing?u003c/strongu003e

Thermal imaging monoculars can detect temperature differences under clothing. This can be used when a person is hiding a gun or any other form of weapon. The image is developed based on the temperature gradient.u003cbru003e

u003cstrongu003eCan thermal imaging devices see-through walls into the building?u003c/strongu003e

The answer in one word is “NO”. Thermal devices only detect the heat that radiated from the objects. In general, walls are thick enough to block the infrared radiation. So the device will detect the heat coming out from the wall but it can’t see what is behind it.u003cbru003e

u003cstrongu003eWhat does Emissivity mean in Infrared Imaging?u003c/strongu003e

Emissivity, also known as “E” value, is a measurement of how effectively a body or surface radiated heat. In theory, the value can range from 0 to 1. But, in reality, the value rangesu003ca href=u0022https://www.flir.in/discover/professional-tools/how-does-emissivity-affect-thermal-imaging/u0022u003e between 0.1 to 0.99u003c/au003e.u003cbru003eFor example, a polished and smooth metallic surface can have an emissivity of less than 0.10. On the other hand, human skin and water have values around 0.98u003cbru003eIn general, if the emissivity of the target is below 0.5 it’s not possible to get an accurate temperature reading through a thermal monocular.u003cbru003e

u003cstrongu003eIs thermal imaging dangerous?u003c/strongu003e

Not at all! Thermal imaging is just another technique to see in the dark which is risk-free. Everything that emits infrared radiation is detected and recorded as an image or video by a handheld thermal monocular.

Conclusion

So it all adds up to this.

A thermal monocular is an excellent gadget to assist you in various outdoor situations. Moreover, it’s also effective for security purposes and search and rescue operations.

Obviously, the choice of the device will depend on your level of usage and the budget. Keep in mind that the best thermal vision technology is expensive. So make sure that you choose a dependable brand with the right reputation.

I hope this article has been helpful in clearing up the various aspects related to thermal monoculars to you.

Now that you have all the information related to thermal imaging monoculars, it’s time to make the right choice.