Posts Tagged ‘ surveillance’



Surveillance Camera Lens

Written By:
Monday, July 11th, 2011

Surveillance camera lens are slowly beginning to evolve with the technology that supports them.  Before the digital age, a good majority of the surveillance cameras required that a lens be purchased for each camera.  Presently, some cameras still work that way, but the vast majority has the lens built right into the camera.  These lenses are often referred to as “board lenses.”

There are three major types of digital video camera based on their shape, the box type, the bullet type, and the dome type.  Basically the bullet and dome type cameras come with a lens already built into the unit.  This is often referred to as a board lens.  The box camera however, almost always requires the purchase of a lens.

As far as the lenses go, there are two different types of surveillance camera lenses, fixed and varifocal.  Fixed lenses do exactly what their name implies; they stay fixed in a certain immobile position.  Varifocal lenses have the ability to change their focal length either manually or remotely depending on the lens.

This means that for fixed lenses, the size of the field of view never changes; the lens can’t alter its own focal length so the width of the capture shot never changes.  This is great for use where there is no need to mess with changing the focal length regularly such as monitoring a parking lot, an entrance or exit, and other uses where zooming in on a subject or object is really not required and the camera will not be moved around a lot.

Varifocal lenses on the other hand, can move in and out changing the size of their focal length.  This is particularly handy when it is necessary to change the camera’s field of view to accommodate moving objects, tight shots, etc.  The focal length of a varifocal surveillance camera lens is normally expressed in millimeters (mm).  For example a fixed camera lens with a focal length of 3.0 mm will produce a fairly wide angle shot, whereas a focal length of 15.5mm will produce a narrow angle shot.

The nice thing about a varifocal lens is, depending on how it is made, you can get a focal length as small as possible and any focal length in between its maximum focal length.  It’s important to note that some of these varifocal lenses must be moved manually (by hand) while some our connected to a motor that drives the lens and is controlled remotely.

As long as we are on the topic of surveillance camera lenses, we’ll also mention a few of the characteristics of lenses that you probably should be aware of in addition to just focal length.  Four other points come to mind:  1. Depth of field; 2. F stop; 3. CS or C mount; and 4. Manual or Auto Iris.

Depth of Field

The depth of field is the distance from the camera to the object at which remains in focus.   Generally, the higher the F stop and tighter the Iris positions, the more objects that will be in focus.  In other words, a large Depth of Field means almost all objects in the Field of View can be in focus.  On the other hand, a small Depth of Field will only allow a small section of the Field of View in focus.

F Stop

The F stop is the foacl length divided by the effective aperture diameter.  In much simpler terms, the F Stop is an indication of the speed of the lens.  Since light must pass through the lens to the sensor, the F Stop gives us an idea of how much light it will absorb during the process.  A low F Stop lens is very efficient whereas a high F stop lens will require a lot of light.

CS or C mount

There are two standard surveillance camera lens mounts the “CS” and the “C.”  The difference between the C and CS is found in the distance between the lens and the CCD (Charged Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor).  The C mount distance is 17.5mm while the CS mount is 12.5mm.

Iris

The iris works with the surveillance camera lens to control the amount of light entering the camera via the sensor.  For cameras mounted in positions that have changing light sources, it is a good idea to use a lens with an automatic iris.  For cameras used inside or in environments where the light conditions seldom ever change, manual irises are sufficient.

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CCTV Systems

Written By:
Tuesday, March 22nd, 2011

The phrase CCTV systems can cover a broad range of different video camera systems.  Generally speaking, when we think of a CCTV system, we are usually referring to a video monitoring, surveillance, and/or security system.  CCTV is an acronym for Closed Circuit TeleVision however, more often then not in today’s age of technology, these systems are often called digital video security and surveillance systems.

CCTV systems got their name because of the way the systems were initially developed.  Closed Circuit Television basically referred to a system by which a video camera transmitted the video images it created through a cable directly to a monitor or Digital Video Recorder or DVR.  This differed from the studio broadcast television that sent their video images through an antenna out to the general public.  Anyone with a television or other type of receiver could view the broadcast audio and/or video image.

Today, CCTV systems are based on the same idea; however, the transmissions are no longer confined to being sent over a dedicated video transmission cable. A CCTV system today may send its video and audio wirelessly on a specific frequency to a specific receiver or they can even utilize the Internet to send their signals just about anywhere in the world (again, to a specific “receiver” or group of individuals).

CCTV systems today share some of the older terminology relating back to the original analog video systems.  For example, older analog CCTV monitors were actually electronic tubes, Cathode Ray Tubes or CRTs to be exact.   These tubes shoot electron beams in horizontal lines on the glass screens to produce a video image.   Thus, the clarity or resolution of these cameras was usually designated by the number of Television Lines or TVLs that it created.  Lower resolution cameras produced around 300 TVL and maximum high definition cameras produce up to 650 TVL.

The cameras and monitors today are digital, and therefore produce their images using pixels, tiny dots of color analogous to the dots seen in newsprint up close.  However, they often still use the TVL designation to define the resolution of the cameras.  One reason for this is that although CRT monitors are seldom marketed anymore, consumers may still have plenty of CRT type monitors they can use for their system.

Today, a complete CCTV system usually consists of one or more digital video cameras, a Digital Video Recorder or DVR, and one or more optional monitors.  Security Camera King offers several complete CCTV system packages to meet just about every security, surveillance, and monitoring need.   Our featured package systems are based on our three signature DVRS, the Elite-Mini, the Elite Series, and the Ultimate Series.

These package systems are further available based on the system being a 4, 8, 16, or 32 channel (camera) system.  Note:  The 32 channel system is only available with the Elite Series DVR.  Finally, we break each one of these packages down based on cable and power supplies.  We offer each system with either “plug ‘n play” pre-cut and connector fitted cables and space saving power supplies or with bulk cable, connectors, and a power distribution supply box.

Our Elite-mini and Elite Series systems come with the appropriate number of 420TVL Vandal Proof Indoor/Outdoor Dome Day/Night Infrared Vision cameras.  The cameras have an approximate infrared range in total darkness of about 50 to 60 feet.  The cameras have an outdoor rating of IP66 and so are very suitable for outdoor or indoor use (our part number for the camera is Product# OD-LX420IR50 for additional details and specifications).

Our Ultimate Series systems come with the appropriate number of 520 TVL Vandal Proof Indoor/Outdoor Dome Day/Night Infrared Vision cameras.  This cameras are true high definition cameras with a resolution of 100 TVL more than those above.  These cameras also have an approximate infrared range in total darkness of about 50 to 60 feet.  They are also suitable for outdoor or indoor use (our part number for the camera is Product# OD-LX520IR50 f0r additional details and specifications).

Security Camera King has put together this system packages to offer you the highest quality yet simplest to install CCTV systems on the market today.  By offering you these as complete system packages, we can make them available at competitive prices that are hard to beat anywhere else for equipment with the same features.  In addition, we allow you to make upgrades if necessary, so that you may “tailor fit” your system to your specific needs.

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Video Surveillance Cameras

Written By:
Monday, March 21st, 2011

Today’s video surveillance cameras have made “leaps and bounds” in technological improvements compared to the cameras from just 10 to 15 years ago.  Not only that, but the camera’s prices have steadily decreased with the increase in technology.  All of this has lead to video surveillance cameras becoming a “household word” for family protection and safety as well as business protection and workplace documentation.

Original video surveillance cameras were based on analog signals.  These systems and components of the systems were often referred to as CCTV or Closed Circuit TeleVision.  CCTV was so named because although it closely resembled a typical television studio system, there was one major important difference.

Studio television cameras’ video signals were boosted by the broadcast station and sent via radio frequency via a large antenna.  Once the signal left the broadcast antenna, anyone with a receiver could pick up the signal.  Video surveillance cameras however, sent their signal along a cable, directly to a specific monitor and recording device.  In this respect, the system was a “Closed Circuit Television” system.  In fact, any system used for monitoring, surveillance, or security in this manner was referred to as a CCTV system.

Today, video surveillance cameras still operate on a CCTV based system, but to be accurate, we must redefine CCTV to make it somewhat looser in application.  Although modern digital video surveillance cameras also transmit their video signals via a cable to a Digital Video Recorder or DVR and one or more monitors, they also employ additional methods for transmitting their signals that must be taken into consideration of the definition of CCTV as well.

These cameras may also transmit their video data wirelessly via an on-board camera transmitter and antenna.  These cameras use modern day wireless technology often used in land-line based telephones such as 2.4 or 5.8 GHz technology or 900Mhz technology for broadcasting their signal.  These systems are designed to transmit their signals only a fraction of the distance of the older systems, as they are aimed at sending their signals to a nearby receiver, which is usually plugged in by cable, to a DVR and/’or monitor.

Another method that is employed today is the use of the Internet as a vehicle for networking and transmitting.  Both video surveillance cameras and DVRs have the capability for connecting to the Internet.  When they do possess this feature they are often referred to as Internet Protocol or IP ready, because they deliver their transmission using IP format technology.

Although it is true that individuals other than who the video images are intended for can gain access surreptitiously, the intent of these wireless broadcasts and Internet transmissions are directed to a limited number of very specific viewers.  Thus, although our definition for CCTV as now become a bit broader in scope, it is easy to see why even today, video surveillance cameras are often called CCTV cameras.

While we are on the subject of CCTV versus new video surveillance cameras, it would be prudent to mention that there is some carry over from the “analog days” of CCTV to the current “digital era” which can make the comparison of components or the selection of a system somewhat confusing.  This primarily involves the use of reference to the detail or resolution of the video image created by the camera and displayed by the monitor.

Electronic video images may show a varying degree of detail.  That is evidenced by the contrast between standard television broadcasts and those called High Definition (HD).  Television was originally displayed on a Cathode Ray Tube or CRT (also called the “picture tube”).  The CRT reproduced the image on its screen by shooting an electron beam horizontally at the rate of about 60 times per second.  To a large degree, the number of horizontal lines determined how detailed the video appeared.  The more lines, the smaller the lines, the greater the detail of the picture.

Today, however, most televisions are like computer monitors; they are either Liquid Crystal Displays (LCD), plasma, or Light Emitting Diode (LED) displays.  These monitors display tiny dots called pixels instead of horizontal lines, therefore, they can display a much higher detail picture.  Yet, many video surveillance cameras still specify their picture quality in terms of the older, horizontal line method.  Its important to know that the lower end of resolution or detail is from about 300 up to 650 TVL (TeleVision Lines).  Video surveillance cameras with 650 TVL displays can produce very high definition video images.

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Security Alarm Systems and Security Equipment Products

Written By:
Tuesday, November 2nd, 2010

Security Camera King, in addition to digital video security systems, offers a full line of security alarm system and security equipment products. This includes counter surveillance, personal protection, and audio recording devices. Supplement your digital video security system with additional security alarms system and security equipment to maximize your protection potential.

If you are looking for cost effective security alarm system and security equipment products to supplement your digital video security system or to use as a standalone alarm system without digital video security, Security Camera King suggests our HomeSafe Wireless Home Security System. This system includes a wireless motion detector and a wireless door/window sensor, a keychain remote control for arming and disarming the alarm system, an AC adapter, and of course a central control panel.

Like most security alarm systems, the HomeSafe Wireless Home Security System works by placing sensors on accessible doors and windows (usually the doors and windows on the first floor). The door/window sensor (often referred to as a point or zone) can detect vibration or door/window opening and will notify the central control panel if that event occurs (often referred to a trigger). However, instead of running a wire from each sensor to the central control panel, this system uses wireless technology to enhance the performance of the system and make do-it-yourself installation quick and easy.

The central control panel can handle up to a total of 9 zones or points (sensors). (Security Camera King sells additional sensors as part of our security alarm system and security equipment products.) When any of the sensors are triggered, the sensor sends a signal to the central control panel. The panel then initiates a 105 dB alarm.

If you opt to connect your unit to your telephone line, the central control unit will, in addition to activating the ear piercing alarm, automatically dial up to 5 telephone numbers. When the first pre-programmed telephone number answers, a pre-recorded message will be played. Plus, that party will have the option of listening in on the room, broadcasting their voice through the central control unit, or disarming the system. If the first number dialed doesn’t answer, the unit will continue by dialing the second number and so on.

The central control unit has a 16 digit display that includes date and time and is easy to setup and program. It also provides for remote arming and disarming by telephone. The unit also uses a standard 9 volt battery (not included) for backup in the event of a power failure.

Security Camera King also offers counter surveillance devices as part of our security alarm system and security equipment products. Our Wired or Wireless Camera Multifunctional Detector can “sniff out” radio frequencies emitted by cameras and microphones ranging from 1 MHz to 6 GHz. This device also includes an LED signal strength meter and audible or vibrating alerts. In addition to radio frequency detection, this device also uses laser visual detection to find camera lenses, from wired or wireless cameras, up to 10 feet away.

Security Camera King also has bug detectors as part of our security alarm system and security equipment products. These detectors cannot locate the bug, but they can tell if there is one anywhere in the immediate area by “sniffing out” 1 MHz to 3 GHz radio frequencies.

We also carry a wide selection of various personal protection equipment including:
• Airsoft guns
• Animal repellent
• Car safety devices
• Diversion safes
• Folding knives
• Handcuffs
• Mace Pepper Sprays
• Personal alarm devices and
• Tasers and stun guns.

If you are looking for audio recording devices we offer two 576 hour digital phone/room recorders. These are professional grade recorders that also have a built-in FM radio. Voice activated, Line-In input, and MP3 encoding are just some of their available features.

So remember, Security Camera King doesn’t just sell digital video equipment but we sell a variety of security alarm system and security equipment products. If you have any additional questions about our products or a specific product, check them out by clicking on the appropriate category on the left hand side of our web page or click on the “Live Chat” button at the top of the page or call 866-573-8878 Monday through Friday from 9AM to 6PM EST to speak with one of our security experts.

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Security Cameras Monitoring Systems

Written By:
Friday, October 22nd, 2010

Some of the most popular items used for protection and surveillance today are security cameras monitoring systems. These systems take advantage of the latest and greatest in both electronic and computer technology making them incredibly powerful and versatile to use. In addition to deterring burglary and/or vandalism, security cameras monitoring systems offer you the peace of mind of knowing that your business, residence, or loved ones are okay.

Most security cameras monitoring systems are component systems; that is, parts of the system may differ in function (i.e. one camera may have Pan-Tilt-Zoom or PTZ and another may not) or may be made by different manufacturers (i.e. the cameras may be produced by one manufacturer while the DVR is produced by another). Regardless of the differences between components, all of the separate parts can work together to create a functional and effective security camera monitoring system.

Security cameras monitoring systems work in the following manner. The digital video camera “captures” a light image and transfers it into an electrical image. This electrical based image is sent in the form of electronic data to the DVR or Digital Video Recorder. The DVR normally contains a special type of computer processor known as a Digital Signal Processor or DSP. The DSP compiles the data from the video camera and creates a digital video file of the data which can e stored on the DVR or viewed in real time (live) on a monitor.

The DSP normally uses a COmpression/DECompression or CODEC utility to make the digital video file smaller without sacrificing quality. This is necessary because digital video files are comprised of thousands of digital photographs. In fact, they are digital photographs, but they are taken at a high rate of speed, usually around 30 photographs or Frames Per Second or 30 FPS.

This means that for every one second of video, the file will contain the equivalent of data for 30 individual digital photographs. As you can see, the file can get very large in a hurry so a CODEC is a vital and necessary tool.

The security cameras monitoring system may also include a CD/DVD writer, SD card writer, or accommodate a USB thumb drive for archiving files or for providing copies of files on a portable media to police, insurance agencies, etc.

There are a variety of optional features available for digital video security cameras however it may be easier to differentiate between cameras if they are categorized first, based on two of these features. The first criteria to use for categorizing the cameras can be the shape of the camera itself. There are three basic shapes or types:
• Box shaped cameras;
• Bullet shaped cameras; and,
• Dome cameras.

Box shaped cameras look just like the name implies; they are rectangular shaped to resemble a small box. These cameras may be mounted on walls, ceilings, and other structures. Bullet shaped cameras are elongated and rounded in shape on the ends to resemble a bullet-type structure. They may also be mounted on walls, ceilings and other structures. Finally, dome shaped cameras are usually flush mounted on ceilings with a rounded dome protrusion just big enough to allow for the camera lens.

The second criteria for categorizing digital video security cameras is whether they are designed for indoor use, outdoor use, or both. Indoor use only cameras cannot be used outdoors because they may be damaged by exposure to dust, water, and other debris. Outdoor security cameras monitoring systems or indoor/outdoor cameras are enclosed in a protective case that allows the camera to function properly but prevents entry (ingress) of dust, water and other matter.

Many outdoor cameras will be certified according to the protection the enclosure provides using a International Electrotechnical Commission (IEC) standard called an Ingress Protection code or IP rating. This code consists of two digits; the first digit represents protection from dust and the second digit represents protection from liquids. The first digit of the rating ranges from 0 to 6 and the second digit ranges from 0 to 8, the higher number indicating a greater rate of protection. An IP65 rating for example, means the enclosure is dust tight and provides protection from water projected by a nozzle against the enclosure from any direction.

There are many other option features available on the components of security cameras monitoring systems. If you are interested in additional information, check our knowledge base or security articles or contact one of our security experts today.

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