Equation CCTV Camera: Essential Calculations for Choosing and Planning a CCTV System

Planning a CCTV system involves more than selecting cameras and mounting them in suitable locations. A few simple equations can help estimate camera coverage, image detail, storage requirements, network bandwidth and power consumption. Understanding these calculations makes it easier to design a system that meets the needs of a home, shop, office or industrial site.

This guide explains the most useful CCTV camera equations in straightforward terms. The results are estimates; actual performance will depend on the camera, lens, settings, scene conditions and recording method.

Field of View and Lens Selection

The field of view (FOV) describes how much of a scene a camera can capture. A wider FOV covers more area, while a narrower FOV shows more detail in a smaller area.

A useful formula for estimating the horizontal field of view is:

Horizontal FOV = 2 × arctan (sensor width ÷ (2 × focal length))

Here, sensor width and focal length must use the same units. For example, if the sensor width is 6.4 mm and the lens focal length is 4 mm:

Horizontal FOV = 2 × arctan (6.4 ÷ 8) ≈ 77°

This is an approximate angle. Camera manufacturers may state the FOV in the product specifications, and the exact value can vary with the sensor and lens combination.

For a rough estimate of the scene width covered at a particular distance, use:

Scene width ≈ distance × sensor width ÷ focal length

For instance, with a 6.4 mm sensor width, a 4 mm lens and a camera positioned 10 metres from the subject, the approximate scene width is 16 metres. This simplified estimate assumes a level view and does not account for every lens or installation factor.

Pixel Density and Image Detail

A camera’s resolution alone does not determine whether it can identify a person, read a number plate or recognise an object. The amount of image detail available at the target location also depends on how wide an area the camera covers.

A basic pixel-density calculation is:

Pixel density (pixels per metre) = horizontal image resolution ÷ scene width in metres

If a camera records 2,560 horizontal pixels across a scene 20 metres wide:

Pixel density = 2,560 ÷ 20 = 128 pixels per metre

A narrower view places more pixels on a smaller area, which can improve detail on a specific target. However, it also reduces the overall area being monitored. Choose the camera’s position and lens according to what the system needs to capture, rather than relying on resolution figures alone.

CCTV Storage Calculation

Storage depends mainly on the camera’s bitrate, the number of cameras and the length of time recordings must be retained. A practical estimate using decimal gigabytes is:

Storage (GB) ≈ bitrate (Mbps) × recording hours × 0.45

For continuous recording over several days, use:

Storage (GB) ≈ bitrate (Mbps) × cameras × hours per day × days × 0.45

For example, one camera recording continuously at 4 Mbps for 24 hours a day over 30 days would need approximately:

4 × 1 × 24 × 30 × 0.45 = 1,296 GB

This is an estimate, not a guaranteed drive requirement. Variable bitrate, motion-based recording, frame rate, image complexity, audio and recorder overhead can change the final amount. Allow additional capacity and check the recorder or storage manufacturer’s specifications.

Network Bandwidth Calculation

For a network video recorder or remote viewing setup, estimate the total camera bandwidth by adding the bitrates of all cameras:

Total bandwidth (Mbps) = sum of the camera bitrates

For example, eight cameras each transmitting at 4 Mbps produce a combined stream of approximately:

8 × 4 = 32 Mbps

In practice, network capacity should include additional headroom for overhead, other network traffic and bitrate variation. Remote viewing also uses upload bandwidth at the site. Check whether the camera or recorder uses a separate lower-resolution stream for remote viewing, as this can reduce bandwidth use.

Power Budget Calculation

For a camera powered by a direct-current supply, electrical power can be estimated using:

Power (watts) = voltage (volts) × current (amps)

A camera operating at 12 V and drawing 0.8 A uses approximately:

12 × 0.8 = 9.6 W

For a Power over Ethernet (PoE) installation, add the power requirements of all connected cameras and compare the total with the switch’s available PoE budget. Allow for devices such as infrared illuminators, heaters and motorised lenses, which may increase power demand. Always follow the equipment manufacturer’s electrical and PoE specifications.

Putting the Equations to Work

Before installing a CCTV system, identify the areas that need monitoring and decide what each camera must achieve. A wide overview camera may be suitable for monitoring a large entrance, while a narrower view may be needed to capture useful detail at a counter or gate.

• Use the field-of-view calculation to compare lens options.
• Estimate pixel density to check how much image detail may be available at the target distance.
• Calculate storage based on bitrate, recording hours and retention period.
• Add the camera bitrates to estimate network requirements.
• Check the combined power demand against the power supply or PoE switch budget.

Conclusion

The right CCTV camera system is designed around its purpose, not just its technical specifications. Equations for field of view, pixel density, storage, bandwidth and power provide a useful starting point for planning. Treat the results as estimates, confirm them against product specifications and test camera views at the site before finalising the installation.

CCTV Camera FAQs: Prices, Working, Wi-Fi Requirements and Hikvision vs Prama

1. What is CCTV camera price?
2. What is the mechanism of CCTV camera?
3. Which brand is best for CCTV camera?
4. Can CCTV work without Wi-Fi?
5. Which is better Hikvision or Prama?
6. Which brand of CCTV camera is best?
7. What is the Fullform of CCTV camera?
8. Is Prama a company of Hikvision?

What is CCTV camera price?

The price of a CCTV camera varies depending on its resolution, lens, night-vision range, storage options, connectivity and features such as motion detection or weatherproofing. The total cost may also include a recorder, hard drive, cabling, installation and ongoing maintenance. For an accurate estimate, consider the number of cameras and your site requirements, then request a customised quotation from Sonal Enterprises India.

What is the mechanism of CCTV camera?

A CCTV camera captures light from the scene through its lens and focuses it onto an image sensor, which converts the light into an electronic signal. The camera processes this signal into video and sends it to a recorder, monitor or network device through a wired or wireless connection. Depending on the system, footage may be viewed live, recorded for later use or accessed remotely. Infrared LEDs in some cameras provide illumination in low-light conditions, while motion detection and other features can help manage recording and alerts.

Which brand is best for CCTV camera?

There is no single “best” CCTV camera brand for everyone; the right choice depends on your budget, site requirements and support needs. Compare image quality, night vision, recording options, cybersecurity features, compatibility with your existing system, warranty and the availability of authorised service in India. Brands such as CP Plus, Hikvision, Dahua, Axis and Bosch offer options across different requirements, but it is wise to check current product specifications and local support before deciding. For the best result, choose a camera suited to the area and have the system installed by a qualified professional.

Can CCTV work without Wi-Fi?

Yes, a CCTV system can work without Wi-Fi. Wired cameras can connect to a digital video recorder (DVR) or network video recorder (NVR) using cables, while some wireless cameras can record to a memory card or local recorder without an internet connection. Without Wi-Fi or internet access, you may not be able to view footage remotely or receive app alerts, but local recording and monitoring through a connected screen can still work. Check the camera’s specifications to confirm its recording and connectivity options.

Which is better Hikvision or Prama?

Neither Hikvision nor Prama is automatically better for every CCTV installation; the right choice depends on your requirements, budget and local service availability. Compare the specific models for resolution, night vision, field of view, storage and network compatibility, as well as warranty and support in your area. For a reliable choice, select the camera that best suits the site and ensure it works with your existing recorder or CCTV system.

Which brand of CCTV camera is best?

There is no single CCTV camera brand that is best for every requirement. The right choice depends on your site, budget, image quality, night vision, storage needs, warranty and after-sales support. Compare trusted brands such as Hikvision, CP Plus, Dahua and Axis, and check that the cameras are compatible with your recorder and meet relevant security requirements. For an Equation CCTV system, confirm product specifications and support availability with the supplier before purchasing.

What is the Fullform of CCTV camera?

CCTV stands for “Closed-Circuit Television”. A CCTV camera captures video and sends it to a limited, designated set of monitors or recording devices, rather than broadcasting it publicly. These cameras are commonly used for security and surveillance in homes, shops, offices and public spaces.

Is Prama a company of Hikvision?

PRAMA is an Indian video-security brand, and PRAMA Hikvision India Pvt. Ltd. is associated with Hikvision in the Indian market. However, the exact corporate ownership and relationship should be checked against the companies’ latest official disclosures; PRAMA should not automatically be described as simply a Hikvision product line. When choosing a CCTV camera, check the product’s manufacturer, warranty and authorised service arrangements.