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ATN ThOR 4 640 Thermal Rifle Scope

ATN ThOR 4 640 Thermal Rifle Scope Review

The ATN ThOR 4 640 thermal riflescope is a great choice for hunters looking for thermal rifle scope with top-of-the-line optical performance and HD video recording and streaming.

It offers a best-in-class detection range, high refresh rate, and superior image clarity for a very reasonable price.

A new feature in the ThOR 4 series is dual HD video recording and streaming. You can simultaneously record video on an SD card and stream on the ATN Obsidian app.  

Of course, these features don’t come cheap.

If you are looking for a more budget-friendly alternative, see our reviews of the best cheap thermal scopes.

Or keep reading to learn more about this fantastic series of thermal scopes from ATN.


  • Resolution: 640x480
  • Detection range: Depends on lens (max 3300 yards)
  • Refresh rate: 60Hz
  • Display resolution: 1280x720
  • Video recording: Yes at 1280x960 @ 60 fps
  • Video streaming: Yes
  • SD card max capacity: 64GB
  • Weight: 2.35bs (with 4-40x lens)
  • Operating temperature: -20°F to +120°F
  • Warranty: 3 years

ATN ThOR 4 640 Features

ATN ThOR 4 features

Here are the top 10 features of the ATN ThOR 4 640 thermal scopes.

1. Extra-Long Detection Range 

The ATN ThOR 4 640 offers the longest detection range of any popular thermal riflescope. 

The longest-range model (4x-40x) can detect human-sized prey from as far as 3,300 yards, making it possible to track game from more than a mile away.

The identification range is much closer but is still an impressive 800 yards.

2. 640x480 Resolution

The ATN ThOR 4 640 also offers the highest sensor resolution found in thermal scopes, 640x480.

More pixels allow the ATN ThOR 4 640 to gather more thermal information from the environment.You’ll see targets in better detail, even during the day when there is less temperature difference between targets and the background.

The high resolution allows the scope to detect animals as far away as 3,300 yards and provide a zoom as high as 40x.

With lower resolution scopes, image quality deteriorates quickly when you zoom.

3. HD Display with Multiple Color Palettes 

Forget fuzzy and grainy displays that distort what you are seeing. 

The 1280x720 HD display on the ThOR 4 640 scope displays crisp and sharp images.

Even when you zoom, the image remains relatively sharp with minimal distortion.

Like other thermal scopes, you can cycle through different color palettes for a better view of your target. Options include white hot, black hot, and color mode. 

4. One-Shot Zero Sighting 

Zeroing a rifle scope is essential for shooting accuracy.

This process is easy and quick, with the ThOR 4 640.

You only need to take a single shot to sight the scope, hence the name one-shot zero sightings. This ensures you are ready to hunt in no time.

5. Ballistic Calculator 

atn thor 640

Accuracy is not all about zeroing your scope. When you are out in the woods, a wide range of factors, including wind, temperature, and humidity, affect your shot accuracy.

To increase your chances of dying on shots every time, the ThOR 4 640 comes with a built-in ballistic calculator.

The ballistic calculator uses multiple kinds of data to automatically adjust the reticle. 

Some of the data, like barometric pressure, is measured automatically from the internal sensor.

Other data points like temperature and relative humidity require manual entry.

You’ll also need to enter your rifle and ammunition’s information, including drag function, bullet weight, and initial velocity.

If you have multiple rifles, you can have separate profiles for each, so you don’t need to enter the information every time you switch rifles.

The ballistic calculator replaces complicated charts and calculations. It also saves you the inconvenience of using a separate ballistic calculator app or software.

The ATN ThOR 4 640 does all the calculations for you and sets the reticle at the right spot.

6. Smart Rangefinder 

A laser rangefinder is the most accurate way of calculating distances to targets. If you don’t have one, the ThOR 4 640 has a built-in smart rangefinder.

The ballistic calculator uses information from the rangefinder to center the reticle.  

7. Smart Mil-Dot reticle 

The smart mil-dot reticle further improves shooting accuracy. The reticle makes it easy to choose the best holdover position, compensating for bullet drop because of gravity.

You can also use the mil-dot reticle to calculate approximate range to your target, though you don’t need to since the smart rangefinder does that for you. Trijicon has a helpful blog post on how to use a mil-dot reticle to calculate the range.

Unlike most mil-dot reticles that only work at specific magnifications (usually the base or highest zoom), the smart reticle in the ThOR 4 640 is dynamic.

The reticle adjusts the mil points as you zoom in on your target, as shown below.

Another great thing about the smart mil-dot reticle is that you can use it with the ballistic calculator (another advantage of having a built-in ballistic calculator instead of a separate one).

The ballistic calculator crunches the numbers for you and automatically shows you where to place your holdover using a teal dot. 

8. Dual Video Streaming & Recording with RAV

This is a new feature in the ThOR 4 series. With the ATN ThOR-HD series, you could record video and stream it, but not both at the same time.

With the new Obsidian Core, the ThOR 4 640 can stream live video via the Obsidian app while also recording to an SD card. You don’t have to choose between recording important moments and sharing them live with other people.

What’s even more impressive is that the scope can record and stream HD video. The video resolution is 1280x960 at a frame rate of 60 fps. The high frame rate is handy when recording a moving target. `

To make sure you don’t forget to record the most exciting moments, the ThOR 4 640 has recoil activated video or RAV.

When you turn RAV on, the scope will save a video recording from a few seconds before, during, and after the shot. Video recording is triggered by your rifle’s recoil, and you can adjust how long it records before and after the shot.

To make sure your rifle’s recoil is powerful enough to trigger RAV, the ThOR 4 640 has a RAV calibration feature in the settings. 

9. 16+ Hours Battery Life

With all these awesome features, battery life surely must be terrible?

Surprisingly, it’s better than in other scopes with fewer features. The lithium-ion battery provides at least 16 hours of continuous use.

The battery is bigger than in other scopes, but that’s not the only reason it lasts longer. The new dual-core processor, though powerful, runs cooler and more efficiently.

ATN ThOR 4 640 Lens Options

ATN ThOR 4 640 Lens Options

The ATN ThOR 4 640 is available with four lens options, each with a different magnification range. Here are the four lenses with the detection, recognition, and identification ranges for each.

  • 1-10x (least expensive) – 830y detection, 350y recognition, 225y identification
  • 1.5-15x – 1050y detection, 530y recognition, 330y identification
  • 2.5-25x – 1950y detection, 800y recognition, 475y identification
  • 4-40x (most expensive) – 3300y detection, 1450y recognition, 800y identification

ATN ThOR 4 640 Product Specifications

How Easy is it to Use?

If you have used a thermal rifle scope before, it should be easy to get started with the ATN ThOR 4 640. If this is your first thermal scope, there’s a bit of a learning curve.

Because the ATN ThOR 4 640 has so many features, we recommend taking your time to go through the manual and going through the menus and settings.Learn how to mount the scope on your rifle and zero it. Also, get familiar with the video recording and streaming settings before you go out to hunt.

You don’t want to miss an important moment because you are fumbling around in the menu to find the record button.

Overall, it takes more time to get started with the ATN ThOR 4 640 compared to cheaper scopes. Even experienced hunters will need time to get used to the new features.

But once you know your way around the scope, you’ll discover it’s easier to use than other scopes. 

Features like the ballistic calculator, smart rangefinder, and smart mil-dot reticle make hunting much easier and more accurate, especially for beginners.

Advantages of ATN ThOR 4 640 Thermal Rifle Scope

The ATN ThOR 4 640 works impressively for long distances. Some advantages that you can expect are: 

Ultra-Low Power Consumption

Low power consumption makes the ATN ThOR 4 640 reliable for long hunting spells. 

The ThOR 4 640 has a battery life of 16+ hours that is sure to last you a complete day of hunting and spottingThis continuous battery power makes it a far better choice than scopes with a battery life of 5 to 10 hours. 

Plus, the ThOR 4 640 has a USB-C cable that you can use to recharge it anywhere.

You can even connect it to a power bank to charge the battery quickly when you need it. It doesn’t take long to charge, either. 

And even though the battery lasts a long time, it is pretty lightweight.

So, if you want a rifle scope that consumes less power while running smoothly, this is one of the best options.

Dual Stream Video

The Thor 4 640 is compatible with both Wi-Fi and Bluetooth devices, so you can stream videos on any device of your choice. 

Also, it has a RAV (Recoil Activated Video) feature that automatically activates video recording even when you forget to do so.

You can set up a timer to start the RAV before making a shot. The RAV stops recording after the shot as per the timer that you set while setting up the scope. 

For instance, you can set a RAV for 30 seconds before and after the shot if you want a 60-second video of your shot.

In addition to live-streaming videos, you can transfer them to a micro SD card. 

ATN ThOR 4 640 Problems

This remarkable thermal rifle scope suits most hunters’ needs. But, there are a few downsides that you should know. 

Image Quality Issues

Image quality is something that most users complain about. They report that the images become grainy on using maximum magnification. 

Some users also complain about dead pixels, but that can be resolved by running the pixel correction protocol. 

Scope Similar to the ATN ThOR 4 640: Pulsar Thermion XP38

Pulsar Thermion XP38

Like the ATN ThOR 4 640, the Pulsar Thermion XP38 is designed for hunters looking for a high-performance thermal scope and don’t mind paying more to get top of the line optics.

The two rifle scopes are in the same high price range though we think the ATN ThOR 4 640 offers more value for your money.

Here’s how the two scopes compare on important features and specs.


Pulsar Thermion XP38

Thermal resolution



Detection range

3,300y with 4-40x  

1,050y with 1.5-15x 

1,500y with 1.5-12x

Display resolution



Frame rate

60 Hz

50 Hz

Video resolution



Video streaming




SD Card (max 64GB)

16GB internal storage


2.35bs (with 4-40x lens)



3 years

3 years

As you can see, the ATN ThOR 4 640 outmatches the Pulsar Thermion XP38 on most specs for roughly the same price.


atn thor 4

Looking to upgrade your ATN ThOR 4 rifle scope?

Here are the best accessories from ATN.

  • ATN ABL Laser Range Finder with Bluetooth for accurately calculating distances to targets. It attaches to the ATN ThOR 4 scope.
  • ATN Quick Detach Mount that can be moved from rifle to rifle without losing zero.
  • ATN X-Trac Remote Control with Bluetooth gives you an easy and convenient way to use the ThOR 4’s menu. Has buttons for moving through menu options, zoom, and video recording.
  • ATN 20,000mAh Battery Pack gives you an extra 22 hours of continuous use. Combined with the 16-hr built-in battery, you can go hunting for days without requiring a recharge.

Where to Buy

About the Author Rob Carson

I work in commercial construction, in Dallas, TX.

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