Thermal Imaging

What is thermal imaging?

All objects, both natural and manmade, emit infrared energy as heat. By detecting very subtle temperature differences of everything in view, infrared (or thermal vision ) technology reveals what otherwise would be invisible to the naked eye. Even in complete darkness and challenging weather conditions, thermal imaging gives users the ability to see the unseen. Thermal sensors detect heat emitted by objects, converting it into an electronic signal to generate a thermal image. This allows you to see temperature differences in the scope's field of view. 


Applications in Various Fields


·Detection Advantage: Thermal scopes like the Sytong Thor 5 640 make hunting at night, especially for hogs, varmints, and coyotes, incredibly effective. The heat signatures of these animals stand out against cooler backgrounds, even in total darkness. 

·Example: A hunter using an Sytong Thor 5 640 can easily spot the warm heat signature of a coyote moving through dense foliage, a scenario where traditional night vision might not be as effective. 


·Target Acquisition: In shooting, especially in low-light conditions, thermal technology helps shooters quickly identify targets. 

·Example: A shooter practicing at a range with dim lighting can use a thermal scope to better see and aim at targets that would otherwise blend into the dark background. 

Home Defense: 

·Intruder Identification: Thermal imaging plays a crucial role in home defense by allowing homeowners to detect intruders based on their heat signatures, providing an advantage in darkness or obscured conditions.

· Example: If an intruder hides in the bushes at night, their heat signature can be easily detected with a thermal imaging device, alerting the homeowner. 


·Perimeter Surveillance: In security, thermal imaging is invaluable for monitoring large, dark areas where potential threats could hide. 

·Example: Security personnel patrolling a large, dark property can use thermal imaging to quickly spot human figures, even if they are camouflaged or hiding in shadows. 



Thermal sensor size

The resolution of the thermal sensor, specifically the microbolometer, serves as a crucial parameter in evaluating sensor quality. It denotes the number of sensitive elements (pixels) that form the sensor, and a higher pixel count in sensors contributes to the production of more detailed images of objects. Standard sizes for thermal imaging sensors are: 


Sensor resolution

Aspect ratio






Pixel Pitch and Thermal Imaging Sensor Measurement

When delving into the intricate technical specifications of a digital image sensor, one will inevitably encounter a critical metric known as "pixel pitch." In essence, pixel pitch is the width of an individual pixel on the sensor, usually expressed in microns (μm). This simplifies the calculation of the overall physical sensor size—just multiply the resolution by the pixel pitch. However, confusion arises when considering how these sizes impact thermal sensors' field of view and detail levels.

Unlike standard visible sensors, where increasing resolution without altering sensor size enhances image detail, thermal cameras follow a different paradigm. In thermal imaging, elevating resolution while maintaining the pixel pitch yields the same level of detail in an image but with a broader field of view. 

In the context of pixel pitch differences, let's explore the distinctions between two common values: 17 microns and 12 microns. 

17 Microns Pixel Pitch: 

A pixel pitch of 17 microns implies that the centers of neighboring pixels are situated at a distance of 17 micrometers from each other. Sensors with this pixel pitch are likely to be larger in physical size, and this can offer advantages such as improved light sensitivity. The larger pitch can be beneficial in applications where a higher sensitivity to infrared radiation is crucial. 

12 Microns Pixel Pitch: 

On the other hand, a pixel pitch of 12 microns indicates a smaller distance between pixel centers. Sensors with a 12-micron pixel pitch are generally more compact, allowing for higher pixel density within the same physical sensor size. This can result in increased image resolution and finer details, making them suitable for applications where a high level of detail is essential.