In this guide, we show the 9 best thermal scopes to highlight their pros and cons to help you make a purchase decision. 

As infrared technology advances in the past few years, the thermal scopes have changed too, and this list narrows down these thermal scopes based on overall performance, low light detection and identification performance, weight, battery life, and cost.

Top 6

Best Clip On

trijicon hunter ir

Trijicon Hunter IR 24mm

Magnification: 1.2X

Refresh Rate: 60 Hz

Weight: 28.4 oz

Best Overall

ATN THOR 4

ATN THOR 4 640

Magnification: 1-10X

Fresh Rate: 60 Hz

Weight: 30.88 oz

Lightest Weight

Trijicon reap IR

REAP IR 24

Magnification: 1-8X

Fresh Rate: 60 Hz

Weight: 24.7 oz

Best Price

sightmark photon rt

Sightmark Photon RT

Magnification: 6-12X

Refresh Rate: 60 Hz

Weight: 32.8 oz

Best Technology

sightmark wraith

Sightmark Wraith

Magnification: 4-32X

Refresh Rate: 60 Hz

Weight: 36.3 oz

Best For Mid Range

AGM adder

AGM Adder TS35 384

Magnification: 3-24X

Refresh Rate: 50 Hz

Weight: 31.4 oz


Thermal Scope Applications - Do You Need It?

ballistic calculator thermal scope

Thermal scopes can provide the following usage:

  • Heat signature detection for hunting
  • Detect target movement that night vision scopes can't

Use night vision and thermal technology for hunting, tactical shooting, home defense, and sport with these comparisons:

Hunting & Recreation: Choose a night vision scope for clear and natural images, reliable hunting, better animal details, and a wider field of view in open environments. Go for a thermal optic in foggy or dense areas to easily detect game.

How Does A Thermal Rifle Scope Work

Here is how a thermal rifle scope works: A Germanium lens in the thermal sight captures thermal radiation from objects and focuses it, similar to how a glass lens in a day optic sight focuses regular images.

This focused thermal radiation is then converted into an image using a converter called Thermal Core. This image, along with reticles, is displayed on the screen for the user to aim at the target. However, human eyes cannot see thermal radiation directly, making the use of a thermal scope necessary.

Clip On (COTI) VS Dedicated Thermal Scope

Thermal Scope Clip On

Referenced thermalopticsplus.com

Clip On

Clip on (COTI) thermal scopes go in front of the primary optic to add thermal capabilities when provided with a good mount. This is a versatile and cost effective option that works with most magnified scopes as long as there is room to mount the thermal scope in front of the optic.

Pros

  • Adds thermal capability to normal rifle scopes
  • Quickly detach when not needed

Cons

  • Long scope length can take away mounting spot (Can work for short LPVOs) 
  • It doesn't work on rifles with not enough rail space
  • Reduced detection range because it's smaller

Dedicated Thermal Scope

Pros

  • Much better image quality and thermal detection range
  • More interfaces and user controls
  • Designed to withstand recoil
  • For serious hunting and farm land protection uses

Cons

  • Much more expensive
  • The thermal components are much more sensitive to environmental elements such as moisture
  • More care is required

Base Magnification

The spec on thermal scope magnification has an effect on image resolution and refresh rate, which can cause lag.

Thermal Detection Range

High end thermal scopes have detection range up to 4000 yards while budget options are in the 1000 yard range. 

The detection range is in direct relationship to the lens diameter and angle of view. The larger the diameter the smaller the angle, which gets the user more detection range.

Refresh Rate

For hunting and accurate target detection without lag, a thermal scope with at least 30 hz.

Higher refresh rate in the 50 - 60 hz will drive up the price.

Weight

Trijicon reap IR thermal

The weight of a thermal sight directly impacts a hunting experience just like other scopes. While it may not be a big concern in a scenario where one always shoots from a steady tripod or prone position, it becomes a factor when shooting from a standing position after a brisk walk. 

Carrying a heavy sight for several hundred yards can cause fatigue and affect stability since most thermal scope shooters are hunters attempt to protect their properties from wild animals and predators. 

Video Recording Feature

thermal hunting hogs

Having video recording feature isn't a must have, but it's a cool add on feature to capture hunting kills

Thermal Core Pixel Pitch

thermal core pixel pitch

Referenced opgal.com

All thermal sights sold produce high-quality thermal-to-visual image conversion due to the use of Vanadium Oxide thermal cores, which are the industry's best. Lower quality thermal cores result in lower quality images. The image below illustrates this information.

  • Thermal Core converts thermal image to displayable picture with specified number of pixels (Thermal Core Resolution)
  • More pixels result in better image quality when magnification is increased (e.g. 640 x 480 is better than 384 x 288)
  • Higher magnification thermal sights need less digital magnification, 384 x 288 still provides high-quality image
  • Thermal Core Pixel Pitch affects native magnification of scope -Closer pixels (smaller Pitch) result in higher native magnification (e.g. 12 µm pitch cores > 17 µm pitch cores)

Thermal Resolution

  • Higher thermal scope resolution leads to clearer and more detailed image
  • Magnification of the scope also affects image quality
  • It's important to find a balance between resolution, magnification, and other factors such as Thermal Core Pixel Pitch
  • Digital zoom is not the same as true resolution -Digital zoom only increases the size of the image on the screen and does not add detail or clarity
  • True resolution refers to the actual number of pixels in the image captured by the sensor
  • A higher true resolution means a clearer, more detailed image

NETD

thermal scope NETD

NETD stands for "Noise Equivalent Temperature Difference." It is a measure of a thermal imaging device's sensitivity to temperature differences and is used to determine the smallest temperature difference that the device can detect.

40mk NETD range ensures perfect detection even in harsh weather conditions when thermal contrast is low.

Lower NETD values measured in micro Kelvin (mK) indicate higher sensitivity and the ability to detect smaller temperature differences, resulting in a clearer and more detailed thermal image.