Posts Tagged ‘ security camera’



Closed Circuit Security Camera

Written By:
Thursday, July 7th, 2011

The closed circuit security camera has been used for decades. But when the digital world began to affect the digital video security and surveillance world, it opened up numerous new features never available before that made this type of system versatile, powerful, and simple and easy to use.

In addition, digital cameras became lighter, circuitry came on very small Integrated Circuit Chips (IC chips), and all of these things contributed to driving prices down so that systems were much more affordable for individuals and not just big corporations or the incredibly wealthy.

Closed circuit security camera systems also known as Closed Circuit TeleVision or CCTV have evolved over the years and have come a long way technologically speaking. Older analog system cameras were pretty large and bulky, but today’s cameras are so small they can be hidden in the head of a Phillips screw!

Let take a look at the evolution of closed circuit security cameras and some of the features and options they offer today.

The original closed circuit security cameras were direct spin-offs from the television studio camera.   In the studio, the camera captured a video image, processed it somewhat, and passed it along to the editing room where any necessary changes could be made or added.  The signal was then sent through amplifiers that increased the signal’s power tremendously and sent it through a huge outdoor antenna.

Once the signal made it to the antenna it was “broadcasted” as far as the strength of the signal could go.  Anyone with a receiver, in this case a television, could “pick-up” these video transmissions and watch was being recorded.  Since the signal was just emitted in any direction and to any person wishing to view or hear it, the system was referred to as an open broadcast system (those of us that didn’t care to get too technical just called it “TV”).

CCTV or closed circuit security cameras worked on the same premise.  A video camera would capture a video image and then send it along a video transmission cable.  However, this is where the similarity ends because CCTV typically did not “broadcast” their video using an antenna.

Instead, cabling was used and was where the video image signal remained.   In order to see the video that was being captured an individual or video recorder would have to be connected to that cable.  Since all the components of the system were connected in one way or another, usually via the video transmission cable, this was referred to as a “closed circuit” hence the name “Closed Circuit TeleVision” or “CCTV” or specifically in the security industry, closed circuit security camera.

Granted, there are wireless cameras that have their own transmitter and antenna built right into the camera, but these cameras are on a special frequency and cannot be picked up with an ordinary TV.  So in essence, even though we still may broadcast security camera signals, these signals are only meant for the people that are designated to use the system.  Therefore we can “stretch” the meaning of the phrase “Closed Circuit Security Camera” to include even these cameras, since their transmitters and receivers still maintain a somewhat “closed circuit.”

In addition to wireless technology, here are just a few of the features available today with close circuit security camera:

  • - Night time Infrared technology.  The sensor chip in the camera is inherently sensitive to near infrared radiation as well as visible light.  These cameras can be used in conjunction with InfraRed Light Emitting Diodes or IR LEDs.  The human eye cannot see the IR LED light source, but the camera can.
  • - Pan-Tilt-Zoom or PTZ cameras.  These cameras can move horizontally or vertically and also zoom in on objects.
  • - Hidden or disguised cameras.   We sell a product (our product# HC-SCREW-W) as small as a Phillips head screw that contains a camera.
  • - IP ready (Internet Protocol) cameras contain their own web server technology and can be accessed by almost any computer or smartphone connected to the internet.
  • - Cameras with two-way audio.
  • - Object tracking or following.   Some PTZ cameras have the technology built right in to the camera to track or follow objects or people.

These are just a few of the things available with closed circuit security cameras.   For a more detailed look, check out our online catalog at http://www.securitycameraking.com.   You’ll be glad you did, we’ll guarantee it.

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Zoom CCTV

Written By:
Thursday, June 30th, 2011

One of the most popular digital video security system features is the zoom CCTV or Closed Circuit TeleVision.  There are many different types of Zoom CCTV cameras designed for a multitude of uses; be sure when shopping for one that you get the features you need.

What is a “zoom CCTV” anyway?   It’s a digital video security camera used in CCTV that can vary its lenses focal length enough to enlarge objects farther away from the camera and make them appear closer (enlarged) and with more detail.  These lenses are often referred to as varifocal.

Most box cameras that do not have built in lenses so they have the advantage of using Zoom CCTV lenses only.  These can be manual lenses where they are basically positioned through trial and error by hand or they can be remotely controlled as well.

There are also some cameras that do have on-board lenses that zoom only and these are often found among the bullet type and dome type cameras.  When we say “Zoom” only, we are referring to just the zoom function, as compared to a Pan-Tilt-Zoom or PTZ camera which has additional features including the ability to move horizontally or vertically.

Security Camera King has a wide selection of digital video cameras including cameras that can zoom.  Examples of varifocal lens “zoomable” bullet cameras that they offer include:

Security Camera King also has plenty of dome cameras with zoom capability.  General these lenses are “fixed” to the camera and cannot be changed.  This type of lens is often called a “board lens.”  They may also offer digital zoom as well.  Here’s a partial list of their Indoor Dome Cameras:

Security Camera King has plenty of outdoor zoom CCTV cameras also.  Once again, here is a partial list of their “Vandal Resistant” dome cameras that have zoom capability:

We’ll save listing the PTZ cameras when we write about them but of course, if it says it’s a PTZ camera, than it must have a zoom lens.

If you have any additional questions about zoom cameras and whether your situation calls for one or not, please contact one of security experts.   You may contact them via on-line “Live Chat” or by telephone at 866-573-8878.

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Multichannel Security Camera

Written By:
Monday, June 6th, 2011

A multichannel security camera usually refers to a wireless security camera that has more than one frequency that it can transmit its video (and audio for some) data over to a corresponding receiver.  The multichannel aspect is important to prevent cross talk, interference, or other reception problems.

Let’s begin our discussion with multichannel security cameras by reviewing how a “wired” digital video security system works.

The digital video camera is responsible for “capturing” the video image.  It does this by using one of two different photosensitive sensors.  One is called a Charged Coupled Device or CCD and the other is called a Complementary Metal Oxide Semiconductor or CMOS.  Although they both work a little differently, they both produce the same end result; data that can be used to construct a digital video image.

Generally the CCD or CMOS sensor is only 1/4 to 1/3″ square.  When light focused from the lens strikes the surface of the sensor, it emits a small electrical charge that can be measured.  This is used to construct the digital video image, but first the data must pass through a specialized Integrated Circuit or IC chip called an analog-to-digital converter.  The data also passes through another IC chip called a Digital Signal Processor or DSP which refines and fortifies the quality of the image

After passing through these components, the digital video data is now ready to be sent to the Digital Video Recorder or DVR.  The signal is sent along a cable or wire; many different types may be used but the most common is RG59 coaxial cable.  Using the proper adaptors CAT5 cable is also used.  The key here is that the video transmission must be “shipped” over a cable from the camera to the DVR.

Once the data reaches the DVR additional DSP chips compile the data and create a digital video file which can be stored for later use or viewed in real time (live).  The DVR uses something called a CODEC which stands for COmpression/DECompression utility.  The CODEC shrinks the size of the file incredibly while maintaining a high degree of quality.  The CODEC also prepares the file for streaming over the Internet if this is an option.

A wireless digital video security system basically works the same way.  The difference is the multichannel security camera contains its own transmitter circuitry and antenna.  It uses radio waves instead of RG59 or other cable to send the video signal from the camera to the DVR; most of the time this done using a corresponding receiver unit that is plugged into the video input of the DVR.

This is analogous to a land line wireless home phone.  The hand set has its own transmitter/antenna and it sends and receives signals to the base unit (receiver).  However, because land line based wireless home phones are so popular, it could be very easy for someone in the surrounding neighborhood to be operating on the same frequency as your phone.  This can happen with digital video transmissions as well.

Therefore these cameras are equipped with a selector that can be moved to choose a variety of different radio frequencies, or in this case, “channels.”  This can be a confusing term for the novice digital video security enthusiast because the word “channel” is also used to mean number of cameras or other devices.

So a multichannel security camera is a digital video security camera that has more than one radio frequency that it can transmit over.  Generally, the more channels available the better.  For example if you have an 8 channel (camera) DVR the wireless cameras will need 8 separate radio frequencies (channels) to prevent interference.  Likewise, the receiver will require the same or you may be able to use one receiver per camera, which could get a bit tedious.

If this article has not shed some light on what a multichannel security camera is, please contact one of our security experts via 0n-line “Live Chat” or by telephone toll free at 866-573-8878 Monday through Friday from 9AM to 6 PM EST.  They will be happy to explain any additional information and help you with the design, installation, set up, and use of a Security Camera King multichannel security camera system.

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Security Camera Computer

Written By:
Tuesday, May 31st, 2011

The security camera computer of a digital video security and surveillance system is basically the “brain” of the system.  This is where the COmpression/DECompression or CODEC utility is normally used to shrink the size of the incredibly large digital video files made by the security camera.  The security camera computer is also the central controller for the entire digital video system, coordinating all the actions of the components in the system.

Another name that is more commonly used instead of security camera computer is Digital Video Recorder or DVR.  Although admittedly, there are some systems where the DVR is only a storage device and does not control the entire system.  Let’s start from the beginning to see just exactly what a security camera computer does.

An average digital video security surveillance system is a component system that consists of three major components (it may have more or less depending on the system).  The components are the digital video cameras, the DVR, and the monitor.  Note that the phrase “security camera computer” did not appear anywhere in the previous sentence, although the functions of a security camera computer are normally considered the tasks of the DVR.

The digital video security camera creates an electronic based video by converting the light images gathered by the lens and focused on a special sensor chip.   The sensor chip contains pixels that when struck by light emit an electronic pulse that can be measured, interpreted and used to create and electronic recreation of the field of view of the camera.

Interestingly, up to this point, everything has been in analog format.  The camera has a special processor called an analog-to-digital processor that converts the analog information into digital data.  Cameras normally contain another processor that helps to stabilize and improve the display of the digital video.  This processor is called a Digital Signal Processor or DSP.  Once the data has been processed by the camera it is sent to the security camera computer (or DVR).

There are basically three types of security camera computer.  The first we’ve already mentioned; it is the most popular type of security camera computer in use today and is called the DVR unit.  While it’s true the major function of the DVR is to process and store digital video files, it generally coordinates the activities of all the other components within the system.

For example, the DVR (or security camera computer) is either responsible for or performs the following actions for the digital video security system:

  • CODEC application – the security camera computer uses a CODEC utility to shrink the size of the digital video file while maintaining as much original detail and quality as possible.
  • Operation of special uses cameras – The Security camera computer may also be equipped to control special use cameras such as a Pan-Tilt-Zoom or PTZ camera.  It may include programming the automatically initiates the PTZ camera to “lock on” on track or follow a specific object (such as a car in a parking lot).
  • The security camera computer also coordinates activities within the DVR itself.  For example, many DVRs are capable of recording several cameras at once while simultaneously playing back previously recorded video.
  • The DVR may also contain the components required to access the Internet and make controlling the system form anywhere in the world that 3G or 4G smartphones can operate.

The second type of security camera computer is the Network Video Recorder or NVR.   The NVR typically doesn’t control as many accessory type functions as a DVR.  The NVRs role is to coordinate the use of single or multiple Internet Protocol (IP) ready cameras.  This could mean that a camera could be placed at one address and another in a totally different location (such as a different city) and by using the Internet is able to “network” these cameras as is they were one local system.

Finally, the third type of security camera computer is, of all things, a computer!  These systems usually have plug and play PCI cards that are installed on the computer.  The PCI card may perform a great many of the functions that are needed using the computer only for storage purposes on its own hard drive.  Nonetheless, this is a type of security camera computer.

As you can see, the security camera computer performs a great number of tasks in addition to storing the digital video files.  It truly is the “brain” of a digital video security system.

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Internet Security Camera System

Written By:
Tuesday, May 17th, 2011

Nothing has more “global” access in the digital video security camera industry than an Internet security camera system.  The outreach available for use and/or monitoring has been extended even further with the increased technology in cell phones, namely 3G and 4G broadband Internet access.  In the following article we’ll take a look at some Internet security camera systems and how they work.

First, let’s make sure we understand how a “non-Internet” security camera system works.   In this type of system, digital video security and surveillance cameras capture video footage and send the video data to the Digital Video Recorder or DVR.  The DVR stores the video on a hard disk drive (HDD) just like the HDD found in a personal computer.  In addition the DVR may also display the video in real-time (live) on one to many monitors for surveillance purposes.

The digital video camera is responsible for capturing a light image and transforming it into an electronic image.  It does this by using a lens to focus what can be a large field of vision onto a small electronic sensor which usually ranges in size from 1/4 inch to 1/2 inch square.

One of two different sensor chips is used for this purpose.  They are the Charged Coupled Device or CCD and the Complementary Metal Oxide Semiconductor or CMOS. When light strikes these sensors they emit electrical charges which can be measured and used to create a video image.  The data that is created by these chips is actually analog in form until it passes through an analog-to-digital converter chip.  Another highly specialized electronic chip called a Digital Signal Processor or DSP insures the integrity of the data and may make any corrections that are necessary.

At this point, the camera passes the digital data along to the Digital Video Recorder or DVR whose job is to record the data and store it as mentioned above.  It does this by compressing the file into a fraction of its original size but still managing to maintain a high quality.  It does this by using a COmpression/DECompression or CODEC utility.

An Internet security camera system is very similar to this type of system, however once the data becomes digital, it opens up a whole new world of possibilities, especially including the use of the Internet.  There are basically two types of Internet security camera systems.  One system consists of cameras that are Internet compatible also called Internet Protocol ready or IP ready.  The other system consists of a DVR that has its own Web server technology and is called IP ready as well.

IP ready cameras contain their own web server technology so that they maybe connected to the Internet.  Instead of sending their digital data directly to a DVR, they send their data via the Internet to anywhere there is a client that wants to access the information.  Generally these cameras use two CODECs at once.  Many of the cameras pass the information on to the DVR using the MJPEG CODEC while streaming the information via the Internet for live viewing using the latest CODEC H.264.

These cameras may direct their video via the Internet to a specific type of DVR that is designed for this purpose which is called a Network Video Recorder or NVR.  One of the advantages of this system is that multiple cameras in multiple locations can be recorded by the NVR.  These locations can be widespread, such as two or more commercial facilities that are located in two different cities.  An Internet security camera system of this type can lend itself to all sorts of networking possibilities.

Another type of Internet security camera system exists where the DVR is the IP ready device and it takes care of all Internet related inquiries.  In this system, the cameras are not IP ready and they send all of their digital data to the DVR.  The DVR then contains its own Web server technology and allows a client access to the system through the DVR.  All of Security Camera King’s featured DVRs have these feature built in to the DVR.

This internet security camera system records the video locally on the DVRs HDD, but it allows a user to control the DVR and in many instances, even the cameras (for example, PTZ movements) remotely.  As a matter of fact, these systems can ever be monitored and controlled using a smartphone and 3G or 4G Internet technology.

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