CCTV cameras

CCTV cameras

Cameras are one of the components that directly affect the quality of a CCTV system. That's why you have to pay more attention when choosing a camera. Let us now see the types of CCTV cameras and how they are used.

 1. Dome Cameras

These cameras are installed on the roof or ceiling.  Mostly used as indoor cameras. But can be used as outdoor cameras if equipped with IP protection. 

2. Bullet Cameras 

The name is given because the shape is similar to a gun bullet. Widely used as outdoor cameras but can be used in indoors as well. Most of these are equipped with IP protection and are mostly built with a metal frame. Has an adjustable cap that prevents falling water droplets onto to front glass. 

3. Pan,Tilt and Zoom Cameras (PTZ Cameras)

This type of camera can be rotated horizontally (Pan) and vertically (Tilt) and zoom in on distant objects. Because of that, these cameras can cover a wide range. And some of these cameras have the ability to operate automatically (Auto Pan & Tilt). These are quite expensive in the market.

4. Box Cameras

Box cameras are high-quality CCTV security cameras that offer users the freedom to tailor their surveillance systems to their unique requirements. Users can select weather protection, camera resolution, video signal type, and lens type that fits their needs. Moreover, box cameras enable straightforward replacement or enhancement of the camera, enclosure, or lens configuration. You can effortlessly swap out the camera body to replace the video pickup component, and upgrading or changing the lens lets users adjust the field of view without the necessity of a complete camera replacement. This camera can be used both indoors and outdoors. When used as an outdoor camera, a metal enclosure is used as shown in the picture below.

Well, now let's look at some other things to pay attention to when choosing a camera

1. Camera lens and aperture (LENS & APERTURE)

       CCTV camera lenses can be divided into two main parts according to how they are used

a. Varifocal lens cameras

b. Fixed focal lens cameras

  a.Varifocal lens cameras

             By changing the focal length of the lens of this type of camera, the range of the camera can be changed. The focal length of these cameras can be changed. This can be further understood by the following example. This photo shows a comparison of photos taken with a 10mm to 135mm zoom camera. With this particular camera, we can change the range we want. But we cannot do this task automatically. This change can only be done by the camera. (The focal range of a camera is indicated by f)

b. Fixed focal lens cameras

Because the focus of the lens cannot be changed in these cameras, the camera's field of view cannot be changed. But in some cameras, changing the camera lens can change the capture limit.

Camera Aperture

F is the size of the aperture through which light enters the camera. (eg - F1.4 , F2.8 ,F5.8 ). As this value increases, the diameter of the opening decreases.

2. Quality of the picture

      When choosing a camera, the quality of the images must be considered. Factors that can measure image quality.

a. Resolution

This is referred to as horizontal resolution. The unit in which this is measured is TVL (TV lines). The higher the value, the higher the resolution. (eg - 600TVL ,700TVL). In addition, there are HD-SDI cameras with very high resolution (HD).

b. The camera's CCD or CMOS sensor

Any digital camera produces images using a CCD (Charge-coupled device) or CMOS sensor. The quality of the picture frames varies depending on the manufacturer (eg Samsung, Sony). The size is also mentioned here (eg 1/3”, 1/4”). Some cameras have a CMOS sensor instead of a CCD.

3. Night vision

             Night vision is also very important. Night vision cameras are available in the market. The most popular and inexpensive type of camera is the IR(infrared) illumination camera. This camera is equipped with an IR LED. This IR LED is set to work in the absence of light. In general, IR light is not sensitive to the human eye but is sensitive to cameras. That's why the IR LED gives the camera visibility in situations where there is no normal light.

Apart from this, external IR LED illuminator lamps can be installed outside the camera as well. The IR LED Lamp can provide night vision to any camera. Apart from this, there is another type of camera called IR thermal camera and those cameras are quite expensive.

An IR(infrared) illumination camera

An external IR illuminator

4. Protection against water and dust (IP and NEMA ratings )

In the description sheet of the camera, a value is mentioned as IP or Nema. IP stands for Ingress Protection. You can understand this by looking at the table below. 

Eg - IP66 - This is completely protected from dust and can withstand a huge jet of water from any direction

IP67 – It is fully protected against dust and can be submerged in water up to 1m.

Additionally, there is a similar standard nomenclature called Nema as the table as follows 

By the IP or NEMA rating given by the camera manufacturer, you can decide which type of camera you should install according to the location. 

5. Protection against criminals (Vandal Proof)

Some criminals may try to break cameras to hide from them. It is important to install Vandal-proof security cameras in unpopulated places (eg - closed shops at night). There are special vandal-proof cameras for this purpose. These cameras are equipped with metal and very hard plastic covers. These cameras are very important especially when the camera is installed at a low height.