The Final Chapter for PTZ?

Why high-definition video delivers more than just a pretty picture


There have been a lot of fundamental changes to the way we use CCTV over the last few decades. We started by using it as an extension of our roving guards, extending our eyes to many places. We watched and dispatched. Today, we record. For most companies, the purpose has shifted from watching to documenting. Even for those applications where watching is still important, we tend to do more recording than monitoring. The economics of the situation have driven many to have hundreds of cameras and one operator.
With that in mind, let’s ponder our old friend, the pan/tilt/zoom (PTZ) camera. For seeing a detailed view over a long distance, there is nothing better today than an optical zoom on a camera with a pan and tilt mechanism. In fact, for some applications, a PTZ is the only reasonable answer. There are, however, four key issues with a PTZ. These issues are important enough to make us investigate other ways to get the job done.
Someone has to be watching the image in order to operate the PTZ. In an era where most captured video goes unwatched, that defeats the purpose. Odds are that the camera will be pointed away from any incident that occurs. While it is true that video analytics is beginning to show promise at being able to operate a PTZ for tracking purposes, most applications like a parking lot demand more to aim a PTZ than analytics can deliver today.
If you are zoomed in on one object, you have lost awareness of all others. If you decide to have a closer look at the scruffy looking guy that just walked into the lobby, you will not see the slip-and-fall that takes place while you are zoomed in. A key reason for posting a guard in a lobby is a human’s ability to view an entire situation in a room and pay attention to, at times, multiple targets. With a PTZ, how much of that situational awareness is lost?
If one operator has zoomed in on a situation, no other operator can view anything else with that camera. If you are fortunate enough to have multiple operators monitoring your system, the other operators will in all likelihood have lost their ability to view key areas of your site.
Perhaps most important is the effect on recording. For most companies, the ability to forensically go back in time and review a scene looking for information and evidence is why they bought the CCTV system. How does that get done when the cameras are, by design, pointed toward only a tiny fraction of the total scene? “If I am not looking at it, I am not recording it,” says Raul Calderon, vice president of business development for Arecont Vision.

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