How Far Can A Security Camera See (Learn How to Use a Calculator)

If your concern is how far can a security camera see, you must understand a little bit about camera’s field of view (FoV), resolution, and distance. 

Poweful Lens to Represent How Far Can A Security Camera See

Knowing how far your security camera can see will give you an idea with regards to where and how you can better set up your surveillance system. Therefore, leaving no blind spots. So let's dive into this topic, just keep reading...

A home security camera usually can see in a range between 0 to 70 feet depending on the resolution, sensor and lens it's using. However, there are also professional cameras such as high-resolution PTZs that can see further away, with a distance that varies from 0 to 700 feet.

The answer to the question of how far a security camera can see is a little bit more complex depending on the specifics. Let's understand more about this subject.

Get Ready To Learn How to Calculate How Far A Security Camera Can See

The purpose of this article is to give you information as to how you can determine the range limit or line of sight of your security camera system. 

==> By the end of this article you'll be able to calculate how far a home security camera can see and identify a person or a vehicle, I will give all the details and a link to download a powerful 30-days trial calculator you can use for free.

That is, including night time monitoring. You will also be learning about some recommendations of what the best outdoor security cameras are with a long-range line of sight, based on your security needs.

The security camera visible range

You can manage the potential security risks of your premises by knowing the range limits for your security cameras, thus avoiding points of intrusion.

The first thing you must know is how far your security camera can identify some suspect person or vehicle before they get to close to cause some damage.

security camera installed on the road for traffic

Before buying your new camera that promises to be the best thing out there, make sure you will be able to identify or recognize somebody's face or a car's license at a certain distance, such as somebody at 50 feet from your front door. 

So, make sure you know what you want before start looking for a camera. Do you want to identify somebody or recognize a face ? What the maximum distance this person should be from the camera ? Do you want to monitor a large or small area ?

You also need to take into consideration if the camera will be installed indoors or outdoors since the lighting, obstacles, and weather can make a huge difference.

==> To learn more about outdoor security camera, read the article: How to choose the best outdoor security camera.

After deciding what you want, you can calculate which type of camera you need to meet your expectations (you will see more about calculators later).

What Factors Can Influence the Line of Sight of Security Cameras

There are several questions regarding the line of sight of security cameras.

You might ask about the security camera’s line of sight, how far it can see, and also how much it can see. To find answers to these questions, here are some factors which must be considered.

Field of View

Field of View is very important for surveillance camera projects because it describes which part of the scene you can see and that depends on the type of lens and the camera has and how it's adjusted.

The wider the field of view, the more you can see of your scene but fewer details are available since the objects appear smaller and far away from the camera.

The pictures above are part of the Ultimate Security Camera Guide. If you want to learn more consider purchasing this product.

To have the field of view you want, you either buy a camera with the correct focal length or buy a camera with a varifocal lens that allows you to control the camera's field of view by adjusting some screws manually or remotely.

Focal Length

The focal length is the distance between the center of a lens or curved mirror and its focus. This is the most important factor to consider so you can determine how far your security camera can see.

The wide field of view of your security camera is due to the smaller focal length.

In other words, the larger focal length makes the field of view of your security cameras narrower and the objects seem to be bigger and closer to the camera.

It is measured in millimeters and  classified into:

Fix focal length

Security camera with fixed lens

This type of lens has a fixed distance from the camera sensor and the angle of view is always the same. There's no way to change it after buying it.

It's possible to find fixed lenses with 2.8mm, 3mm, 6mm, etc.

The higher this number, the narrow the field of view.

Variable focal length

Security-camera with varifocal lens

Security cameras with varifocal lenses can be adjusted for a wider or narrower field of view by just turning a screw (or remotely when the camera has a motor).

The picture below shows a box security camera that has an interchangeable varifocal lens, which means you can buy the camera and lens separately according to your needs. Can you see this lens goes from 5 to 40mm ? 

Box security camera with varifocal lens

You can adjust the FoV (Field of View) to have a narrow or a wide-angle.

That's why this type (box) of cameras are very popular for special projects where it's necessary to capture image for LPR (license plate recognition).

It's not common to find this type of cameras at regular consumer stores since they are for the professional market, so usually, you can't find them at Best Buy or any other place you use to buy security cameras for your home or small office. 

It's important to understand that the lenses are the primary component that affects the field of view and how far a security camera can see.

That's why I suggest you make an effort to understand the concept.

Watch the video below to have more detailed information...

Did you watch the video ?

I promise you it's not hard to understand the concept, you just need to make sure you can assimilate such knowledge to able to use the calculator I will show you later in this article, so get ready for it!


Resolution is another factor worth considering. It would be useless to install a security camera which can see things but cannot make out details.

Therefore, before considering how far your security camera can see, especially at night, you should try considering the quality of the images your security camera can capture and record.

See if it can give clear videos with vivid details, regardless of how far and the time videos were taken, so you will be able to check for specific details in the footage.

In short, check its resolution. HD security cameras are now affordable. 

You can have 2MP, 4MP, 5MP or even 4K security camera systems at low prices. 

If you multiply the number of pixel in the horizontal by the number of pixels in the vertical you will have the total number of pixels in the image...

See the picture below with the example: 1920 x 1080 = 2,073,600 pixels.

Camera resolution example

These types of cameras can provide you with surveillance videos with clear and visible details and that's what you want, isn't ?

Just to make sure you understand the concept, the camera resolution gives you the ability to use digital zoom and amplify the image to check for details.  

The higher the resolution, the better because there are more pixels (small digital dots) that forms the image. So 4MP = 4 million pixels, 5MP = to 5 million pixels and 4K which is a different standard and represents 8MP = 8 million pixels.

So, with more resolution, you can see more details even if the person or object is further away from the camera. So why not buy a high-resolution camera ?


That's something you probably know. It's common sense that if the object is further away from the camera it's harder to see it with good details.

You have to take into consideration how far the person or the object is from the security camera and you can even use this information to calculate if your camera is able to identify somebody at that distance.

As I said at the beginning of this article, you will learn to calculate how far a security camera can see by entering some data in the software, but first, you need to understand what are the factors that will affect the calculation, so keep reading. 


The quality of your security camera also matters when we talk about determining the range which outdoor security cameras can see.

Remember that not all security cameras are the same. That is, even though they are said to have a similar field of view.

When it comes to quality, consider top security camera brands.

These have large customer bases and maybe depended upon when talking about reliability, durability, and of course, quality.

They may be a little expensive, but they are far better than those from unknown brands. And, despite shelling out an amount at first, you will end up with some savings when you opt for security cameras from reputable brands.

In addition to these, high-quality security cameras from top-notch brands come with technical support from the seller when you need their services. They offer after-sales services which unknown brands do not offer their clients.


Where you place your security camera is also another factor to consider. The location of your security camera can effect how far it can see.

To make us understand this factor better, take into consideration where you install your outdoor wireless security camera.

Take note of any obstructions which may affect its view.

By obstructions, we mean concrete floors, large trees, walls, and bricks can weaken your wireless security camera’s signal strength. Therefore affecting the quality of images and videos captured by it, and also influencing how far it can see.

Therefore to achieve the maximum benefit that your security camera can give you, make sure you install it somewhere where there are no obstructions which may affect its performance.

Night Vision Capabilities

Some security cameras come with IR (Infrared illumination) for night vision. In other words, they can definitely see in the dark.

When it comes to how far your security camera can see at night, there are factors which can affect this function. These factors can include lux rating and type of LEDs. This is a little bit too technical, so I won't discuss it here.

But to keep it simple, the ones that come with a better vision and technology are a bit costlier. Thermal cameras can come for cheap like these that have listed or may cost a fortune, totally depending on your requirement.

It's also recommended to have a security camera that is equipped with 3D-DNR (Digital Noise Reduction) function, which allows improving the quality of the image that is captured in dark areas (when the IR is not being used).

You can check all this information in the product specifications. In general, look for a security camera with 3D-DNR, a good lux rating (also known as minimum illumination) and Infrared lights with ICR (Infrared Cut Removal).

Practical examples with the most popular security cameras

Let's take a look at a popular security camera that is sold on Amazon for less than $30. It's the Wyze Cam 2, which has 2.8mm focal length and full HD resolution.

The field of view is basically a combination of the focal length and the image sensor size and gives you the angle that the camera will capture the images at 110º.

See below the camera specs I got from the manufacturer website.

Wyze cam v2

Wyze cam 2

Resolution: 1920 X 1080 (1080p)

Lens: 2.8mm focal length

Image sensor: 1/2.9" CMOS

Field of view: 110°

Just by looking at this information you really don't know if you can identify somebody at a certain distance from the security camera, do you ?

All you know is that your camera can show you things in a 110º angle and capture high-resolution video just because the advertisement says so...

If I ask you "can this camera identify a person sitting 30 feet away, will you be able to answer this question ? Don't be ashamed if you can't.

The truth is that you don't have enough information to assure that unless you use a professional software such as the IP Video System Design Tool.

So, let's take a step further and use this software to answer this question!

Using The Calculator to Check How Far A Home Security Camera Can See

Alright, let's take the Wyze Cam specs and insert into the software.

The picture below shows the following information:

  • Distance from the camera: 30 ft (check the right red square);
  • Sensor format: 1/2.9" (check the left red square);
  • Camera Resolution: 1920x1080  (check the left red square);
  • Focal length: 2.8mm  (check the left red square);
Wyze cam field of view calculation

(click to enlarge)

The red arrow indicates the location of the person that's is sitting 30 feet away from the camera in a green area which according to the software is not enough for identification, meaning you can't recognize who the person is.

The green area is the observation zone, so you can have an idea if it's a man or a woman and what clothes he/she is using but not much more than that.

You can also see the image of a man and a license plate on the left side that represents the image quality your security camera will have. 

So, the conclusion is that you can't identify a person at 30 feet away from a Wyze Cam that has a 2.8mm focal length, 1/2.9" sensor, and 1080p resolution.

After playing a little bit with the software it's possible to find out that at 27 feet  away from the camera, a person can be identified (It's in the yellow zone now).

Ok, now you know how far you can identify a person and that was not hard, right?

C'mon, you just need to download the software and play with it to find out how far a security camera can see. There's a trial version you can use for 30 days.

How to Monitor Places at a Far Distance

If you want to monitor places at a distance, here is what you should do:

  • Use security cameras with varifocal lenses that can give you a wider field of view. Furthermore, it has the ability to zoom in to identity visible details at a distance. That is, without degrading the image quality.
  • Use high-resolution security cameras to increase their ability to deliver usable images and videos from a distance. For instance, 4MP, and 5MP ones.
  • Choose security cameras from reputable brands. This is to avoid possible disputes and unnecessary problems in the future.
  • Make sure that your security cameras are able to see far enough, with clear and vivid details at night.
  • Consider using professional security cameras with high-resolution such as the ones manufactured by Avigilon which has a resolution of 29 MP.


You must understand the range of a security camera if you are planning to acquire one. There are a few very important details which you must know about. These will help you make a decision and thus, assuring you that you made the right choice.

Taking into consideration these important factors, you can decide as to what type of security camera to purchase. However, it is recommended to get one from a reputable brand.

Want to learn more ? 

If you want to become a professional CCTV installer or designer, take a look at the material available in the blog. Just click the links below:

Please share this information with your friends...