What Is An IR Cut Filter?

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For security cameras, whether they be indoor or outdoor, possessing “night vision” is definitely not a “bonus” feature. It is integral to the usefulness of the security camera itself.

Security cameras, depending on the model, are designed with built-in night vision capabilities which perform at various levels.  

Indeed, if a camera that has been designed to have night vision has inferior night vision, this affects its ability to perform its job well – to see what’s going on 24 hours a day – and, hence, the camera then becomes less desirable to the consumer.

With night vision being such an integral part of any home security camera, it is important to know how it works.  

Basically, every bit of ambient light available to your security camera is taken in and used in some way, including infrared light, which is what your camera will use at night in order to be able to “see”, since daylight is no longer present.  

This is why, even in nearly total darkness, an infrared, or IR camera can still capture an image – because there is still enough of this IR light to allow it to do so. 

In fact, there will always be some amount of IR light, even in the darkest of rooms, and even though the human eye can’t detect it, a night vision camera certainly can.

Also, this explains why IR cameras are also known as night vision cameras; because they depend on infrared light to do their job, which is to see at night.

night vision ir cut

There is a “sweet spot”, you might say, with night vision or so-called IR cameras, which is when they capture the best footage. 

This ideal low light range can generally be described generally as “night time” (or how things look outside on a clear night once daylight is gone), which is convenient for homeowners and business owners alike who want to keep an eye on things at night when burglaries often occur.  

Convenient because the night vision / IR camera has no problem adjusting its settings to meet the needs of this type of low light.  

It is important to note here that natural low light conditions are impaired when there are bright lights introduced that can interfere with the performance of your night vision camera, especially when IR lights are in use. 

This is why certain night vision cameras can be impaired by different light levels which might strike the lens at different times, or a nearby light can cause unwanted interference.

This leads us to the question at hand…


What Is An IR Cut Filter?

ir-cut filter

Security cameras that are placed outside (or inside, for that matter), generally have a function that switches them over automatically when they detect a change in light settings, which is why you don’t need to perform any additional actions in order to prepare your security camera for the night – your security camera performs this action by itself.

During the day time, there is still infrared light present but your home security camera doesn’t need it, so it has a specific filter which is called an IR cut filter that automatically switches the camera to a mode where infrared light present during the day time can’t interfere with the footage, thereby distorting it and/or affecting the colors in an unnecessary way.

ir-cut-filter

If a home security camera is meant to be outdoors, it will most certainly have an IR cut filter built-in, in order to do what it needs to do, which is capture clear footage during the day by blocking out IR light, and then at night where it lets in the right amount of IR light to capture the best footage it can at night. 

You can even hear the mechanism click if you listen closely when it switches over.

If we think of the camera lens like an eye, it too has a certain sensitivity to too much light. 

This is comparable to when we need to adjust our own eyes at night, giving us the night vision upon which camera technology is based. 

As you can see, IR cut filters are very useful.  Luckily, they are built in to most security cameras and they do their small but important job without us needing to switch them on and off.