Camera Types

Have you ever asked one of your school friends if you could try on their prescription glasses? And once you have them on, you have a laugh at how funny the world looks!

The same principle works for the installation of a CCTV camera system. It is important to keep in mind what it is that you would like to monitor and what you would like to achieve with the video footage when designing the system.

There are numerous different types of cameras, and this blog serves to briefly discuss some of the most common camera types in the market and where they are ideally used.

Dome cameras

The Dome camera, name says it all.. they are dome shaped! These cameras are most common in an indoor environment and have the functionality to view a clear and fairly broad picture during both day and night. Dome cameras are mainly used for areas that require wide angle viewing and where vandal resistance is an issue. Because of their dome shape, they are harder to move out of position or to smash off their brackets. A potentially negative consideration for dome cameras , however, is that their infrared lamps are usually a little under-powered and may not reach as far as many Bullet cameras. This decreases the distance the camera can see at night – although, due to the wide angle most installers are looking for when installing these cameras, this isn’t usually too much of an issue.

Bullet type cameras

Bullet type cameras are probably the most commonly used cameras. Their name again comes from their shape, with bullet cameras generally being long and thin, with a cylindrical type design. These cameras don’t necessarily have the widest angle of view and do vary in size, depending what distance these cameras monitor up to and some of their added features. Generally, you’ll find Bullet cameras have more powerful infrared lamps, providing better, further night-time vision, and also you’ll find more models with longer lens-lengths, which again enables the camera to see more detail at further distances (remember, wider angle of view = less detail at distance)

Infrared cameras

Also referred to as IR Cameras, Infrared cameras make use of built-in LEDs that ‘light up’ the area in-front of a camera with Infrared light to enable the camera to ‘see’ in the dark of night. Infrared is simply a part of the light spectrum that human eyes are not able to see. Much like Ultra-violet sits just beyond violet on the spectrum and is impossible for our eyes to detect, so Infrared sits beyond red and is also invisible to our eyes. But these Infrared LED’s essentially have the same effect as turning on a spotlight for an IR capable camera. The infrared lighting allows the camera to capture a good image even when it seems to a human observer that there’s no light at all. During the day, the infrared lamps are switched off automatically to conserve energy, but even during the night, the onboard LED’s consume a very small amount of electricity.

Facial recognition cameras

Facial recognition is an advanced, developing feature of some CCTV systems. The feature requires a specific, dedicated camera with very careful thought given to positioning and lighting to get the best results. The system allows us to capture the faces of people who come onto a specific property and to compare these live images to ones stored in a database. If a match is made between a live image and a stored one, an alert can be raised. The system is mostly used to recognise important people entering an area. This can be, for example, VIP’s entering a jewellery store or unwanted persons who didn’t pay the last time they were in a restaurant. Facial recognition is still a relatively expensive feature to install and also has a number of privacy concerns still floating around it’s use in public spaces.

Licence Plate Recognition (LPR) Cameras

Licence Plate Recognition cameras are specially designed to capture numbers and letters from South African licence plates. They are designed with built in hardware and software, which when correctly configured, can compensate for headlight glare, speed and varying plate positions on vehicles to make sure plates are captured under most weather conditions. Similarly to Facial Recognition cameras, the plates recorded by LPR cameras are compared to a database of “vehicles of interest” and alerts can be generated whenever a match is found. In this way, alerts can be automatically sent to the relevant authorities, be they estate security teams or the SA Police Service. The cameras are mostly used in community safety projects, at the entrances to security estates and by businesses that require vehicle identification monitoring. As prime targets of organised crime, Shopping centres also commonly deploy these cameras.

Thermal Cameras

Thermal Cameras have sensors that are actually completely different to the light-detecting sensors that are found on ‘normal’ day/night cameras. Rather than detecting frequencies of light, they detect thermal radiation (most easily understood as temperature). All objects emit some kind of thermal radiation, and a thermal camera will detect the amount of radiation emanating from an object and rendered this to provide an image or video of the scene. Warmer objects are usually displayed towards the white end of the spectrum, and cooler objects towards the black end of the spectrum. That’s why images captured by a thermal camera are most commonly black and white. But even if not black and white, the image will always be some ‘false colour’ scheme as thermal cameras have no way of differentiating between colour (because they are not detecting light at all!). The major advantage of detecting heat rather than light is that heat is generally far hard to camouflage. A person standing in thin foliage dressing in army camo will be quite hard to spot on a regular, optical camera but on a thermal camera the warmth emanating from the person’s body will ensure they are clearly seen through the leaves (which are much cooler). The contrast between a person (at nearly 37 degrees Celsius) and the surrounding environment (usually not higher than 20-30 degrees) also means that people are often very clearly observable on thermal cameras, regardless of how well they try to camouflage themselves. This contrast also means that thermal cameras are very good at detecting people over large distances with some able to do so over Kilometres!

Dual Lens Cameras

Being fairly new on the market, these dual-purpose cost-efficient cameras have two built in lenses in the design of a larger bullet-type camera. One lens is a Thermal camera and the other a standard IR/optical camera. Although the thermal lenses are not usually as long as dedicated thermal cameras, and hence the human-detection distances are not as great, dual-lens cameras can be very cost effective options for perimeter monitoring.

PTZ cameras

Pan, Tilt and Zoom cameras, also known as abbreviated “PTZ” cameras, offer the ability to move and rotate to follow moving objects or automatically perform tours of wider areas that would otherwise require a large number of Bullet cameras. As they often have powerful zoom capabilities, they are also usually equipped with very powerful infrared LED’s, ensuring that the cameras can see and track objects hundreds of meters away.