It’s one of the most common questions that people ask: What far can my surveillance camera see? What’s the distance that the camera can see? What’s the range that the security cameras can detect objects or people?
It’s an important spec because you need to make sure that the installed camera can see/record at the required distance. In this guide, we will talk about the factors that determine the distance at which the camera can actually see things.
Generally speaking, a regular security camera can see in a range between 10 to 70 feet (3-23m) depending on the lens size, resolution, and the type of sensor. But there are other camera types such as PTZ cameras that are able to see at distances over 1,000 feet.
Guide: How Far Can My Security Camera See?
By knowing the distance and the acceptable clarity that the camera can deliver, you can better protect your property and avoid any possible blind spots. The image needs to be clear enough to identify any intruder or detect car features and license plates.
Before purchasing any security cameras, you should inspect your location and find out the distance between the installation point and the main sport under surveillance. Then buy the cameras according to these ranges.
Another thing to consider: do you need to just capture the general area or do you need to detect faces at entrances, license plates, etc.? Most of the time you’ll need regular cameras, but in some cases, you may need special models. Here you’ll get some clarifications.
There are many factors and specs that determine the security camera’s range. Some cameras can see far away but at a more narrow-angle. Others can see at a very wide angle but closely.
You need to understand all these factors and go for the camera that better fits your needs. In fact, the CCTV camera range distance is mainly affected by the following factors.
The Viewing Angle (Field of View)
Field of view is the area of coverage that the camera can ‘see’ within a scene and this depends on several factors. The wider the field of view, the more you can see but fewer details. (the objects appear small and far away).
The narrower the viewing angle, the less scene you can see, but the clearer the image (clear objects, closer distance). The diagram below illustrates the field of view.
The security cameras can come with a fixed viewing angle but some are available on adjustable lenses that enable the user to adjust the viewing angle. For more details, check the next section of this guide.
The lens size
Also known as the focal length, the lens size of the security camera is the number one factor that determines the distance and the angle that the security camera can see. Technically is the distance between the center of the lens and its focus.
The lens size is measured in mm and it comes in two types:
Fixed lens. It’s standard and it’s usually available in 2.8mm, 3.6mm, 4mm, 6mm, 12mm, etc. Once you buy this type of camera, you can’t change the lens size. It’s glued in and fixed.
Varifocal lens. This type is not fixed and can be adjusted in the worksite to better fit the installation needs. The common varifocal lens size is 2.8mm-12mm which means the lens can be adjusted starting from 2.8mm and up to 12mm.
To understand how the lens size correlates to the distance and the viewing angle, remember this:
- The smaller the lens size, the wider the field of view. The camera will provide clear images at a wide viewing angle, but it cannot see clearly at great distances.
- The larger the lens size, the narrower the field of view. The camera will provide clear images at a great distance, but the angles will be narrow.
If you need a wider viewing angle, then you should go for a low lens size camera. If you need more distance and clarity (but narrower angle) then you can go for a 4mm camera (for example if you need to see your driveway). Usually, a 4mm lens camera is good for a distance around 40-50 feet.
Another type of camera is the PTZ style camera (pan-tilt-zoom) which has an adjustable lens size that can be controlled remotely and the distance can go up to hundreds of feet (depending on the model). Obviously, these cameras are expensive.
Resolution enables the camera to make out the details which are important if you need to identify people and objects. The higher the resolution, the clearer the image, especially during the nighttime.
Nowadays the price of high-resolution cameras has gone down and you can get really clear images at an affordable price. For example, 4MP or 8MP cameras provide clear footage and are not that expensive.
You can go for IP security cameras that use network cables or even HD over coax that use coaxial siamese wiring (one for the power, the other for the data). A higher resolution means that the sensor provides more pixels for the picture which in turn generates a clearer, sharper and cleaner image.
For example, a 4MP camera means that the picture is created using 4 million pixels. On an 8 MP camera, there are 8 million pixels on each frame. This makes the digital zoom feel smoother (and cleared). That way you can identify the subjects at quite a distance (40-70 feet). The diagram below shows various resolutions on security cameras.
The installation spot is important on how far away the camera can see, specifically the height where the camera is mounted. Obviously, the farther the object, the more difficult is to see. Unless you choose the right lens (in this case, a higher lens size).
Before adding any camera, you need to determine the distance that you’re trying to see on the camera. Then purchase the camera with the right specs (that can detect the objects in your location). This process is part of the planning and it must be done.
The camera’s quality
There are a lot of factors that create quality on a camera. And not all security cameras are the same; the price tells something about their hardware quality.
The general rule is to avoid cheap cameras, especially the cameras that claim high-resolution and great night vision at a fraction of the price. You should go the medium range or the high-end if you can afford it.
A good camera has good hardware, meaning good sensors, a good processor, good IR light, and reliable software. The no-name cheap cameras miss a lot of this stuff and quite often they don’t even last that long.
Moreover, security cameras from well-known brands are supported by the manufacturer, get firmware updates and the seller provides a warranty.
Table: The distance that the camera can see based on the lens size
Common cameras are the 3.6mm ones that have an angle of view around 90 degrees. This allows you to identify people at around 20 feet of distance. This camera is great for giving a general overview of the area, but it can’t identify people only if they come close to the sensor.
Another type of camera comes with an 8mm lens and it provides a view angle of 40 degrees. This camera will identify people at around 40 feet. So, the viewing angle is narrower, but you can clearly see people at double distance compared with the 3.6mm cameras.
Varifocal cameras come with an adjustable lens size of 2.8-12mm. You can manually adjust it between the ultra-wide 2.8mm to the telephoto 12mm. At 28mm the viewing angle is around 100 degrees but the identification distance is only around 10 feet. At 12mm you will get a 30-degree viewing angle and the identification range at 50 feet.
Another special camera is the 6-22mm varifocal lens camera. At 6mm the viewing angle is around 40 degrees and identifying range at 35 feet. However, at 22mm the viewing angle is around 16 degrees and the identification distance at 80 feet.
If that’s enough, you can use 5-55mm varifocal cameras. This type is used for specific installation conditions and allows identification at around 230 feet (viewing angle is 7 degrees, very narrow). Below we’ve compiled the table that can help you find out how far the cameras can see (accompanied by the viewing angle).
How to monitor spots at a (far) distance?
If you need to monitor a spot that is at quite a distance, here are some tips to help you make the right choice:
- Choose security cameras that come with varifocal lenses, meaning you can manually adjust the lens to get the right identification range. You can install the camera and then play with the zoom toggle until you’re happy with the result. Common cameras: 2.8-12mm or 5-22mm varifocal lens.
- Higher resolution cameras such as 4MP, 8MP, or 4K ones can provide more pixels on the image which creates a clearer, bigger and sharper image.
- If the distance is quite far, you may use PTZ cameras (pan-tilt-zoom). These cameras come with powerful motorized lenses that can be adjusted and the identification range can go up to hundreds of feet (depending on the camera model). Obviously, the PTZ cameras are expensive and large in size.
- Purchase cameras from reputable companies that have good reviews and that support their products.
- Install the cameras close to the monitoring spot.
It’s crucial to understand the viewing angle and the identification range before purchasing and installing any security cameras. You need to inspect the job site and determine where the cameras will be installed and at what distance are they supposed to see.
Then you can get the correct camera. Consult the table above to find out which lens size works better for your situation. If you plan to build a security system from the scratch, you can check out our recommendation list for security camera systems.