What is CCTV ?

Security camera systems have become essential tools for traffic and accident control in a variety of locations around the world.

From a surveillance center, it is possible to view images from all the cameras.

Shops and small businesses also use CCTV systems to prevent theft and possible legal issues involving clients are also aided by CCTV footage.

It is common to have recorded evidence of employees misbehavior to be used in lawsuits.

Sometimes the footage can also benefit the employee, it all depends on the situation recorded by the security cameras.

The first CCTV systems in the world

The first CCTV system was installed by Siemens in 1942 in Germany to monitor rockets launching during the war.

The first commercial version of the CCTV system appeared in 1949 in the USA.

At first, it was not possible to record the images, but only to monitor live what was happening close to the cameras, years later, in the 1970s, analog tape recorders began to become popular and could be used in systems.

How analog systems work

The concept of traditional analog CCTV systems is quite simple, a camera must be connected directly to a monitor through coaxial cables that can carry the analog signal.

The first analog CCTV cameras was a very low-resolution model. It was impossible to observe the details of objects and people with such a camera.

Traditional analog system

The idea of a CCTV system is to generate, store and display the videos on a monitor, the diagram below exemplifies this concept on the 3 blocks.

The CCTV cameras generate the images, a recorder stores the footage and finally, a monitor displays the video from the camera or tape recorder.

CCTV on tapes

Cassette tapes for VCRs were produced on a large scale for use throughout the world in residential and industrial systems, but the technology has many limitations in terms of quality and practicality.

The first recording systems were composed of low-resolution cameras that generated black and white images for display on monitors and store on simple recorders with VHS tapes.

Recording on cassette tapes was done in a linear manner, which made it very difficult to search for recorded evidence since it was necessary to "run the tape" until reaching the point of interest where the event was recorded.

Another major problem with cassettes for to CCTV footage was the quality deterioration of new copies of the tapes.