Can Night Vision See Through Glass?

Whether you’re setting up a camera for surveillance or wondering about tactical scenarios, we’ve got your answers. Read on to see if night vision can see through glass.

Types of Night Vision

There are 3 major types of night vision:

• passive night vision
• active night vision
• thermal imaging

Although it’s commonly referred to as “night vision,” there are actually three different types of night vision available: active, passive and the newest generation, thermal imaging. Active night vision requires batteries to function and utilizes a small infrared light source in combination with a sensor that converts the invisible infrared light into visible green or yellow images. Common applications for active night vision include military, law enforcement and hunting. Passive night vision does not require any kind of illumination source to operate and creates images from reflected ambient light. This process requires a long exposure time so most passive devices have an image intensifier tube that boosts the available light to produce a clear picture. Military personnel use passive night vision systems in many applications, including aviation, ground operations and ship-based platforms. Thermal imaging devices are superior to both active night vision and passive night vision because they produce images based on heat signatures instead of light. They can be used in all conditions, even complete darkness, making them ideal for use in several military applications.

The newest generation of thermal imaging technology is called LWIR or long-wave infrared, which operates on the principle of temperature differentials. Thermal imagers detect objects by their heat signature and are not affected by lighting conditions or fog, which makes them ideal for military applications where soldiers need to see through obscurants. According to BAE Systems, another advantage is that thermal imaging devices don’t need a light source to operate and only use one-tenth of the battery power required by an active device. These features make thermal imagers ideal for military and law enforcement, as well as hunting and maritime applications.

Can Night Vision See through Glass

The short answer is yes, night vision can see through glass. In fact, both active and passive devices rely on light waves that pass through the glass to form an image, so if there’s enough ambient light to see through the window or windshield then a night vision device should have no problem as well. According to one source from defense-aerospace.com, night vision devices are typically rated to work with 80%+ of the light provided by a full moon. If there’s not enough ambient light due to cloud cover or other factors, then you will need some type of infrared illumination source that only the user can see, such as an infrared spotter flashlight.

The only time that night vision won’t work through glass is with infrared illuminators. Often, windows will be tinted or coated and may reflect infrared light which would prevent digital night vision with supplemental light sources from being effective.