On Field of View and Lens Focal Length tab you can use built-in lens calculator to calculate the CCTV lens focal length, camera field of view, pixel density at specified distance and clearly see areas of identification (red), recognition (yellow), detection (green) and monitoring (blue) on the drawing.

Focal Length (measured in mm) – The distance from the center of a lens to the focal point (sensor). The longer the lens focal length, the narrower is the angle of view.

To calculate the CCTV angle of view or lens focal length, you need to know some parameters of the installation. If you need to calculate the CCTV focal length, you should specify the following parameters:

• Distance from Camera – maximum distance from Camera to the target.
• Camera Installation Height – Security camera installation height.
• Field of View: Height – Height of the target (for example 1.8 m or 6ft for people). When you select the Field of View(FOV) Height for the camera installation, the software calculates the camera Tilt.
• Field of View: Width – The other option is to specify FOV width instead of the height. Just enter the desired width of Field of view (viewing area) for the specified camera distance. If you modify FOV parameters, the Focal Length and the Viewing Angles will be automatically recalculated. The other option is to specify viewing angles instead of FOV Width. In this case, FOV and Camera Focal Length will be calculated automatically.
• Camera Sensor Format – CMOS or CCD sensor size (sensor format). You can choose the sensor format from: 1/2.3″, 1/2.5″, 1/2.7″, 1/2.8″, 1/2.9″, 1/3″, 1/3.6″, 1/1.8″, 1/2″, 1/4″, 1″ and 1.25″. Usually, you can find the sensor format in the camera specification. A typical value for network camera with Full HD resolution is 1/3 inch.

See IP Video System Design Tool, CCTV Design Tool, Online Camera Lens Calculator;

To calculate network bandwidth of your CCTV cameras and get the required storage space for video archives you need to add camera types and specify some parameters of your security camera installations:

Part5: Bandwidth and Storage Space Estimation

Picture 1. IP camera bandwidth calculator. h.265 and h.264 storage calculation.

• Resolution – Camera resolution in pixels. You can select resolution from the drop-down list. The list contains most popular PAL and NTSC camera resolutions (like 352×288 CIF PAL, 704×576 4 CIF PAL) as well as some typical network cameras resolutions (like 640×480) including megapixel resolutions (1280×1024, 1600×1200), HD and full HD resolutions (1920×1080) as well as others.
• Compression – Video compression. You can choose from MPEG4, H.264, four levels of Motion JPEG (MJPG) compression (from Low to High) and “RAW Data”. If you use Motion JPEG you can use different JPEG compression levels. If you use low MJPEG compression (level 10) you get best quality of picture and about 10 times lower frame size. If you use Medium MJPEG compression (level 20) you usually obtain a good picture quality and an optimal Quality/Frame Size ratio. With a JPEG level more than 50 your picture became bad for video surveillance purpose.
• FPS – Frames Per Second. Typical FPS for video surveillance system is from 5 to 15 frames per second. In some applications (like CCTV in casino) it is required to use higher speed values (25-60 FPS). Alternative name for FPS is IPS (Images Per Second).
• Days – Required length of video archive in days (24 hours). Used for storage space calculation.
• Cameras – Number of cameras in your CCTV installation with the same parameters.
• Recording % – Estimated motion recoding activity. 100% for constant recording. This parameter is used to calculate disk storage space in case the video is recorded on a schedule or on a motion detector.
• Image Complexity – Frames from some CCTV cameras are more detailed and have a higher frame size.
• Motion % – Motion activity (100% for constant activity). This parameter is used for MPEG4 and H.264 bandwidth estimation.

As a result for each camera type you get:

• Frame Size (Kilobytes)- software can make frame size estimation based on resolution and compression. In some special cases you can measure your real frame size and specify it in this field.
• Bandwidth, (Megabits per second) – How much network traffic is required for these cameras.
• Disk Space, (Gigabytes) – Disk storage space required to store video archive.

At the bottom of the window you can find total bandwidth and disk space required for your video surveillance system.

To make proper bandwidth planning you should know practical the bandwidth values for your network type.

• 1 Gigabit Ethernet: 500 Mbit/s
• 100 Mbit Fast Ethernet: 55-60 Mbit/s
• 10 Mbit Ethernet: 6-7 Mbit/s
• WIFI 802.11g 54 Mbit:  12-25 Mbit/s

The software calculates Frame Size estimations from Resolution and Compression using our own method based on our MJPEG frame size research.

Bandwidth and storage space are calculated using following formulas:

Bandwidth (Mbits) = FrameSize (Kb) * 1024 * 8 * FPS * Cameras / 1000000
Storage Space (GB) = FrameSize (Kb) * 1024 *FPS * Cameras * Days * 24 * 60 * 60* Activity * / 1000 000 000
The recent version of JVSG Design Tool also calculates RAID arrays: RAID1, RAID5, RAID6, RAID10 modes are supported.

You can also estimate bandwidth and storage using JVSG online CCTV storage calculator.
See also: Video Tutorial, IP Video System Design Tool, CCTV Design Tool;

In everyday language the Field of View of Field of Vision, abbreviated as FOV, refers to that area which is visible through any optical instrument, which could be the human eye or a lens.
This definition can be applied to the CCTV parlance and FOV can be defined as the width or height of a scene to be monitored by the security camera.  In CCTV Field of View depends on a number of factors such as the sensor format, the focal length of a lens, and the distance from the objects.

How do you calculate Field of View (FOV)?

A simplified calculation for 1/4-inch CCTV lens can be made using the following formula:

W (horizontal width) = (distance) * 3.2 mm / (Lens Focal Length)

where 3.2 mm is the horizontal size of 1/4″ CCTV sensor (4.8 mm for 1/3″ sensor).

It is very important to use the right lens for desired field of view; otherwise the images on security cameras will not be satisfactory. CCTV security camera lens with fixed focal length are less expensive and give smaller distortions but do not offer flexibility in terms of  field of view choices.

Avoid using commonly available online lens calculators because modern wide-angle cameras have non-standard wide angles (like 110 degrees instead of 85 degrees calculated by outdated Field of View calculators), and only a FOV calculator with a built-in database of camera models can show correct angles and calculate FOV precisely.

Non standard camera angles

Few years ago most of camera manufactures used camera lenses with normal lens and viewing angles for such lens could be calculated using usual ArcTan() formula.

HorizontalAngle= 2 * arctan(SensorSize/(FocalLenght * 2))

But now there are plenty of camera models with non-standard angles.

For example for Hikvision DS-2CD2622FWD-I(Z)(S) the manufacturer has the following angle range specified: from 35 to 106 degrees. Ordinary lens calculators will give a wrong angle range, most likely: from 24 to 85 degrees.

Also for a proper lens selection you should consider both camera installation height and object height. Without taking all these parameters in the picture, the calculation error can exceed 30%.

Field of View Calculator

Here is the new 3D Online Lens Calculator with a built-in camera database.

As a better alternative you can use IP Video System Design Tool, our professional CCTV design software. With that tool you can load a site map, add multiple cameras and see how modification of any installation parameter can affect the camera coverage.

Camera Field of View on 2D site plan (different colors represent camera zones with different pixel density):

Calculating Field of View for cameras on the imported site map or floor plan.

For that Hikvision DS-2CD2622FWD-I(Z)(S) camera the manufacturer specified the angle range from 35 to 106 degrees.

The only way to calculate the horizontal angle or field of view is to use manufacturer’s data and therefore tools with database of camera models, like IP Video System Design Tool show the correct result:

Built-in camera FOV calculator displays the range of viewing angles for the selected wide angle camera with variofocal lens.
 

Watch Video Tutorial

Camera Field of View Simulator

Simulation of the camera Field of View in 3D using IP Video System Design Tool.

 

Field of View Calculator

In action:

 

See also: Lens Calculator

Download trial version of IP Video System Design Tool [for Windows 11/10/8/7, 365 MB]