A security camera allows you to be somewhere else while still being on top of what is going on in your home or business. The field of view of your security camera allows you to see what you want to see in your home, store, or office. How then can you best use the field of view to ensure you are seeing what you want to see?
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You need to position your security camera at the best place possible to see what you want to see. You also need to learn how to use the field of view of your camera at the best angle.
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What is the Field of View?
Security cameras are a vital tool to protect your home or business from intruders. Security cameras are also used to monitor busy areas such as streets for crimes and accidents. The Field of View of a security camera refers to the area the camera can view or see.
Security cameras are a vital tool to protect your home or business from intruders. Security cameras are also used to monitor busy areas such as streets for crimes and accidents.
What a security camera sees is what you will see in your security monitor. The field of view is measured in percentages and is the view between two horizontal borders of an image on the camera. The field of view is the total width and height of the view.
How does Field of View Work?
Visualize field of view as looking through a cone. A wider field of view will produce a larger cone of vision. In-camera parlance, this has some pros and cons.
The lens of a camera balances the focal length and field of view. The focal length is the distance between the lens of a camera and the image sensor when a subject or image is in focus. The focal point is measured in millimeters. Field of view, on the other hand, is what the camera can see. Field of view is measured in percentages.
The lens of a camera balances the field of view and focal length. A short field of view will have a longer focal length. If your camera, therefore, has a smaller field of view, it will see things from a distance or further away. The effect is similar to when you are looking through a telescope.
If your camera, on the other hand, has a wider field of view, your camera will be able to cover a shorter distance. The combination of the focal length and field of view is referred to as the viewing angle.
It is not always the best to have a wider field of view. The size of the camera’s lens also affects the field of view.
The size and type of lens affect the image captured by your security camera. It is therefore critical to choose the correct lens size and type for your security camera.
The Field of View and Kind of Lens
It is important to understand the kind of lens of a security camera because the type of lens affects the Field of View of your camera.
In choosing the type of lens for your security camera, you should make a choice between two major considerations:
- Do you want to see just a small space but in great detail?
- Do you want to see the overall picture?
in other words, if you have a security camera in front of your home, do you want to see only the main door but with a clear picture of it? Or, do you want to see the entire frontage of your home?
It is important that you first decide on what Field of View you want to see before deciding on a particular type of lens. Here is a list of the lens types and their corresponding viewing angles to help you decide.
There are two types of camera lenses for security cameras. Fixed or mono-focal lens and varifocal lens:
Fixed Lens
A fixed security camera lens has a permanently set field of view. You cannot change or adjust its focal length, the field of view, and zoom level. These lenses are typically used with smaller-sized cameras (smaller than the varifocal camera lens). These lenses are ideal for home security cameras.
A security lens camera with a fixed focal length means you get a fixed coverage area that you cannot adjust.
Varifocal Lens
You can adjust the focal length, the field of view, and zoom level of a varifocal security camera lens. This means the zoom level of the lens can be adjusted to increase its field of view and, therefore show a wide area (zoom out).
The field of view of security cameras with the varifocal lens can be adjusted between the top and bottom views. You can for example adjust the focal point from between 2.8 – 12mm and correspondingly adjust the field of view.
You can also decrease its field of view of a varifocal lens and, therefore zoom in to show a close view from a longer distance with clearer details of the image.
A Varifocal lens is typically used in larger-sized security cameras and ideal for businesses more than in homes. It is often used to monitor large areas and entrances. A smartphone app can be used to change its field of view from narrow to wide-angle.
A security camera with a varifocal lens is more flexible. During installation, you can adjust the focal length and correspondingly the field of view. This will allow your security camera to cover a wider area. It also allows you to zoom its lens to achieve a close-up view of a particular object or space.
The Field of View and Lens Size
The field of view of your security camera depends on the lens size (focal point) and likewise depends on what you want to see. Here is a guide on the field of view of the different lens sizes for a security camera.
6mm lens for a 45° field of view
A 6mm lens will show a constricted yet detailed view. This lens is referred to as a telephoto lens and is used to monitor a specific area or object. This security camera lens shows a narrow yet detailed view. Security cameras with this size of the lens is commonly used in a corridor, a doorway, or a car park entrance.
4mm for a 60° field of view
A 4mm lens will show a clear picture from a distance. The reduced angle of view of this lens will give an illusion that things are close to the camera.
A 4mm lens is usually used for identification and detection. Security cameras with this lens is often used in outdoor car parks or a supermarket aisle.
8mm for a 90° field of view
A security camera with a 2.8mm lens is can cover a wide area. It is popularly used indoors because you only need one camera to monitor an entire room.
There are also panoramic security cameras with 180° or 360° fields of view. Security cameras with this type of lens can monitor an extremely wide location
How to Get the Best Field of View (Security Camera Field of View Tips)
How you set up your security camera dictates how effective it will be. The security camera’s field of view is an important aspect of the setup.
The proper set up of your security camera entails taking into consideration the vertical field of view and the horizontal field of view. This is the image you will see from your security camera whether live or recorded.
A Wide-angle is the best angle for maximum security. With a wide-angle, you will be able to see a wider area but not as much detail. However, if you have a high-resolution camera (1080 or 4K), you will see more details.
Here are some tips to get a good point of view for your security camera.
1. Pick the Right Camera
A security camera with a wide-angle lens can capture more objects. The objects have fewer details, though.
Wide-angle security cameras are best if you want to capture footage in a large landscape – large spaces and in businesses.
Wide-angle cameras, however, are not an option if you want to capture something specific and with high details. In this case, you will need a narrow-angle camera.
Telephoto lens for security cameras captures objects from a distance while making them appear closer because of the lens’ focal length.
When using a telephoto lens, a shorter focal length gives a wider view but limiting the quality of the footage (lesser details).
2. Pick the Right Lens
There are many types of lenses you can choose for your security camera. Before choosing the right type of lens, you should understand what each of them can do. You should also know the landscape of what you want your security camera to capture.
When picking a lens type, ask yourself these questions:
- Do you want to capture the overall picture?
- Do you want to see a wide space with less detail?
- Do you want to see a small space with more detail?
It is important to determine the field of view you need so you can decide on the best lens type.
Here are the types of lenses of security cameras as well as their fields of view or viewing angle.
Wide-angle lens
A wide-angle lens has a focal point of 10mm to 25mm and a field of view of between 1100 and 600. Some security cameras can even go over 1100 for a bit more coverage. Security cameras with this field of view get enough width and distance of, for example, an entire yard.
The field of view of a wide-angle camera is wider than that of your eye. It, therefore, has a wider field of view than normal lenses.
Super-wide-angle lens
This lens has a field of view of 180° or more.
Telephoto lens
This type of lens has a focal length of 65mm to 160mm and a field of view of 250 to 100. With this type of lens, the security camera sacrifices a bit of the field of view in favor of the focal point. A telephoto lens can be best described as a standard lens that can be zoomed twice the view.
A telephoto lens tends to have half the field of view of a standard or medium lens. However, a telephoto lens can be zoomed twice its view.
Standard or Medium lens
A standard or medium lens has a focal point of 25mm to about 65mm and a field of view of 600 to 250.
The distance and lens size of your security camera can largely affect its field of view or what you can actually see. In short, the distance between the mounting area of the security camera and the object it is trying to capture affects what the camera can record.
3. Choose the Right Camera Resolution
Your security camera is useless if you cannot decipher the details of captured images. Shift your point of view from how far the security camera can capture or see to how far it can clearly see with great details.
How far clearly and with great details refer to the resolution of the camera. Security cameras with 4MP and 5MP, as well as 4K are now highly affordable. These resolutions can allow your security camera to capture images with great details.
Further reading: Arlo Home Security Cameras Review: Protect What You Love Most
4. Proper Camera Positioning
To get the best field of view you will need to have the best position for your security camera and you will need to consider room positioning and height.
Height of the Camera
You can position your camera at two heights: above the hip level and high up.
The hip level is when you position the security camera to act as some sort of a peephole of your front door or as though you are placing your camera on a table. Placing your camera this way will allow you to see almost everything. There will, however, be some distortions if the room is too small.
This camera angle is best for wide indoor spaces such as the front porch or in the living room. When the security camera is placed on the porch, you will b able to see the street, driveway, and entire front yard.
You can also position the security camera high up and pointing a bit downward. This camera angle is best for indoor and outdoor spaces. This camera position will allow you to see everything. You can use this camera to position the rooms in your home.
If you opt to place a security camera outdoors, it can cover your front and back yard, as well as your garage.
Room Position of the Camera
The height of the security camera will not matter if it is in the wrong place. If you position your camera high up the middle of the room, the footage you will get will have distortion on the sides.
The best place to position your security camera in a corner for both interior and exterior locations. With the camera in a corner of the room, it can cover the longest distance which is from corner to corner.
You can also position the security camera on the tip of the front or back walls of your home. Position it in a manner that it will have a corner view of your front and back yard. The security camera will then be able to see your camera diagonally and, therefore, cover the most amount of space.
Security Camera Field of View Calculator
The field of view of the lens of your security camera is responsible in capturing objects or scenes you want to see. The lens then transmits the image onto the sensor of the camera. Most security cameras use lenses with fixed-focal-length (FFL) to capture an angled field of view.
Security cameras use different focal lengths to provide a variety of fields of view. A field of view calculator can help you determine which lens is right for what you want to see.
You can enter on the calculator the format of the lens, distance of the object from the camera, lens’ focal length and the calculator will give you the expected field of view of your lens. Do the reverse and you will get the focal length of the lens.
If you have an idea of the field of view you need, enter the camera formats and its distance from the object to get the focal length.
How to Adjust the Field of View
If your camera lens has a fixed focal length, you can change its field of view by changing the distance between the lens and the object. You can increase the field of view of your security camera when your lens is farther away from the object you want to capture.
Conclusion
The field of view of your security camera is largely dependent on the focal length or lens size. A larger camera lens will produce a narrow field of view which is usually a security camera with a wide-angle lens.
On the other hand, security cameras with smaller lens sizes can view a longer distance and, therefore, have a wider field of view.
Whether you need a security camera in your home, office, warehouse, supermarket or school, the field of view of your security camera is something you should seriously think of. The field of view of your security camera allows you to see what you want to see.
The field of view of your security camera is what will maximize the use of your security camera.
References:
- “Security Cameras Field of View”, Dicsan, 2020
- Eric Olson, “Guidelines for Setting Camera Field of View”, Security Info Watch, June 17, 2019
- “Field of View Explained: Getting the Right Angle”, Brick House Security, 2020
