Difference Between Night Vision and Infrared

Night vision and infrared are two technologies commonly used to improve visibility in low-light environments. While they have certain commonalities, their core ideas and applications differ.

The ability to see in low-light conditions by amplification of available light is referred to as night vision. Infrared (IR) technology uses thermal imaging to detect and display the heat emitted by objects.

Read this article to find out more about Night Vision and Infrared and how they are different from each other.

What is Night Vision?

The ability to see in low-light conditions by amplification of available light is referred to as night vision. This technique works by collecting and magnifying existing ambient light, such as moonlight or starlight, to form a visible image. An image intensifier tube, which turns photons of light into electrons and amplifies them to produce a brighter image, is often used in night vision equipment. Military troops, law enforcement authorities, and hunters frequently use these gadgets.

The principle behind night vision is easy. When light photons hit a photocathode in a night vision device, they are converted into electrons, which are then accelerated by an electric field and pass through a microchannel plate (MCP). The MCP consists of tiny channels or tubes coated with a distinctive material that amplifies electrons by hundreds or even millions of times.

Night vision devices are available in a variety of types, including goggles, monoculars, and binoculars. Goggles cover the eyes and provide a wide field of view, whereas monoculars and binoculars are handheld devices used for surveillance or scouting.

Modern night vision gadgets use digital image processing to improve image quality and reduce noise. Some night vision equipment additionally has infrared illuminators, which emit infrared light that is not visible to the human eye but can be detected by the night vision device. This allows the user to see in complete darkness.

Based on the technology used in the image intensifier tube, night vision devices are categorised into three generations. The simplest and most affordable type of night vision is provided by first-generation devices, which use a single photocathode and microchannel plate. Second-generation devices use a multi- alkali photocathode and an enhanced microchannel plate design, yielding a brighter image with greater contrast and resolution. Third-generation devices use a gallium arsenide photocathode and a more advanced microchannel plate design, resulting in a clearer and sharper image with a greater range.

Night vision technology has numerous applications. It is often used to navigate and operate in low-light environments by military personnel, law enforcement agents, and hunters. It can also be used for nighttime surveillance, search and rescue missions, and animal monitoring. Some civilian devices, such as security cameras, binoculars, and even cellphones, now include night vision capabilities. However, the use of night vision devices is carefully restricted in many countries, and it is unlawful to use them without formal clearance for specific activities such as hunting or surveillance.

What is Infrared?

Infrared (IR) technology uses thermal imaging to detect and create a visible image of heat radiated by objects. This technique is based on the fact that all objects with a temperature greater than absolute zero (-273.15°C) produce infrared radiation, which thermal imaging cameras can detect.

Infrared cameras create a temperature map of the area by using a detector array sensitive to infrared radiation. The resulting image displays variations in temperature as different shades of grey, with hotter objects appearing brighter and cooler objects appearing darker. Infrared cameras can also be used to measure the temperature of objects by analysing the intensity of infrared radiation emitted by them.

Infrared technology has numerous applications. It is often used in surveillance cameras, security systems, and firefighting to identify the presence of people, animals, or objects in low-light or smoke-filled environments. In industrial settings, it is also used to monitor the temperature of machinery and detect possible defects or breakdowns. In medicine, infrared thermography is used to identify and diagnose a wide range of illnesses, including breast cancer, inflammation, and joint problems.

Infrared technology is classified into two types: active and passive. In active infrared technology, an infrared light source, such as a laser, is used to illuminate a target and detect the reflected light. A laser is used to illuminate a target and detect the reflected light. This is often used in night vision and distance measurement applications. In contrast, passive infrared technology detects infrared radiation emitted by objects without the need for external illumination. This is extensively used in thermal imaging and temperature measurement applications.

Difference between Night Vision and Infrared

The following table highlights the major differences between Night Vision and Infrared −


Night Vision



Amplification of available light

Detection of thermal radiation

Source of Image

Ambient light (moonlight, starlight)

Heat radiated by objects

Image Quality

Amplified and brighter than the original image

Displays variations in temperature as different shades


1st, 2nd, and 3rd generation

Active and passive



Low Cost


Heavily regulated in many countries

Less regulated than night vision technology


Reliant on available ambient light, limited range

Affected by weather conditions, may not detect certain objects


Image intensifier tube

Detector array


In conclusion, while both night vision and infrared technologies are used to improve visibility in low-light environments, their underlying concepts and applications differ. Infrared technology detects thermal radiation to create a visible image, whereas night vision amplifies available light to make a visible image.

Military troops, law enforcement officers, and hunters frequently use night vision; whereas infrared technology is used in security cameras, surveillance systems, and firefighting. The selection between these two technologies depends on the specific application and the environment in which they are used.

Updated on: 15-May-2023


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