Posts Tagged ‘ security camera’



Digital Color CCD Camera

Written By:
Friday, October 7th, 2011

Most video security cameras today are digital color CCD cameras or digital color CMOS cameras.  How do you know which to purchase?  Is one better than the other?  What does CCD and CMOS mean?   Read on to find out the answers to these questions and more.

First let’s describe a digital video security and surveillance system.  It normally consists of three components; the camera(s), the Digital Video Recorder, and a monitor(s).  The camera’s function in this system is to capture a video image created by light reflectance and transform it into an electronic image based on electrical impulses.  Both live and recorded material is played back by the DVR and may be seen by watching the monitor.

So now that we have a general idea of what each component does, let’s talk specifically about the camera and the security camera CCD.

A digital video camera works by using a combination of mechanical (lenses) and electronic (Integrated Circuit or IC chips and printed boards).  Whatever direction the camera may be pointed in, the area that you will see as a point of view from the camera is called the camera’s field of view.  The field of view is the specific area that will constitute the video image.

The field of view can be made larger or smaller depending on the focal length of the lens.  A standard lens has one focal length and therefore one field of view.  Varifocal lenses can vary their focal length (either manually or remotely).  The field of view contains objects that reflect light.  This reflected light is captured by the lens and when in focus, the lens focuses the reflected light on a sensor chip which is usually only 1/4 to 1/3 inch square.

This sensor chip, in our case, is the security camera CCD or Charged Coupled Device (There is another sensor that is used for the same purpose called a Complementary Metal Oxide Semiconductor or CMOS.  Although it works a little differently than the CCD it produces the same results).  As the focused light strikes the security camera CCD, tiny pixels on the sensor emit a very small but measurable electric impulse.  There may be more than one CCD and there maybe the use of one or more filters involved as well.

Once the light strikes the security camera CCD, the CCD gives off its electrical impulses and these are measured and interpreted by the analog to digital processor IC chip.  This is when the video image becomes digital.  As the processing continues in the camera, the camera’s Digital Signal Processor or DSP, in essence another IC chip makes adjustments to brightness, color intensity, contrast, etc. to make sure the video image is of the highest quality.

Once the video image information now binary or digital, is sent to the DVR the DVR stores it or plays it live.  Either the camera or the DVR compiles the binary data and creates a digital video file out of it.   These digital video files are the same type of digital video files that can be watched on a personal computer.

The digital color CCD camera (and the CMOS) have a unique feature about them that makes it even more versatile.  The CCD (and CMOS) is inherently able to see infrared light.  Infrared light is invisible to the human eye, so this makes for a very powerful, useful security device.  Most night time infrared cameras have an array of Infrared producing Light Emitting Diodes or IR LEDs that are arranged around the lens of the camera.   The human eye cannot see their light, but to the CCD, they work like using a floodlight.

In addition to the array of LED’s around the camera lens, IR LED illuminators may also be used.   Illuminators are just a group of more IR LEDs to add more light to the picture.  Some illuminators boast IR ranges of as much as 300 feet when using the illuminator along with the camera’s own lights.

Incidentally, since this type of video imagery is done with only IR light, the image will be in either black and white or monochromatic.  But very seldom will the detail or resolution degrade so the IR video image is as good of quality as the day time color versions.

Security Camera King has a large variety of digital color CCD cameras.  Check our on-line catalog to see all the digital color CCD cameras that we have to offer.

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USB Security Camera

Written By:
Tuesday, September 27th, 2011

USB security cameras are both affordable and easy to install which makes them an ideal choice for security and surveillance monitoring both in the home and at the office, especially if you are not interested in buying a full system.  USB security cameras utilize a personal computer as part of the security system instead of a Digital Video Recorder or DVR.

“USB” is a computer acronym that stands for Universal Serial Bus.  These cameras require a coaxial cable or similar cabling for transmitting their video images to a processor or personal computer.  They do this via the personal computer’s USB plug.

Most USB security cameras do not come with a PCI card that can do most of the processing work for the computer.  Instead the USB security camera relies fully on the processing power and storage capacity of the personal computer.  Often a CODEC or COmpression/DECompression software or circuitry is used to reduce the size of the digital video file while maintaining high video quality.  On a PCI based USB system the CODEC(s) might be hardwired onto the card in the form of an Integrated Circuit (IC) chip.  Most of the time USB security cameras run straight off the computer so the CODEC is usually programmed in the software that must be loaded onto the computer before you plug in the camera.

USB security cameras utilize the USB port on a personal computer to connect to the computer.  In addition, they normally come with software that processes the digital video signal and allows you to use your computer as the processor/CODEC device, monitor, and DVR storage unit.  As you can see, this not only makes these systems easy to install, but reduces the cost by eliminating the expense of purchasing an additional processor, monitor, and DVR.

The computer monitor can be used to view the video, either live or from stored digital files.  The DVR is just like the personal computer’s hard drive disk, so the computer’s hard drive can be used to store the files.  If archiving or transferring the files is necessary, you can use your personal computer’s CD/DVD writer or USB flash drive to copy the files.

USB security cameras provide video at the same resolutions available as stand- alone units.  Cameras normally capture video in full color under visible light conditions and in black and white or monochromatic under infrared light recording.

The cameras in this system use either a Charged Coupled Device or CCD or a Complimentary Metal-Oxide Semiconductor (CMOS) to capture the light transmitted through the lens into electrical energy.  This energy can be interpreted and converted into high quality video.  Due to modern technological advances, these sensors can be highly sensitive to light and produce images in very low light conditions.  In addition, CCDs and CMOSs are inherently sensitive to near infrared radiation which makes them excellent for use as night vision infrared video cameras.  The camera sees the infrared light, normally produced by infrared Light Emitting Diodes or LEDS, but humans cannot see this light at all.

A USB security camera has lot’s of benefits, but they all come at one huge cost.  Regardless of the processor speed and storage capacity on the hard disk, USB video capture really taxes the resources of the computer.  It may be difficult to even try using to USB security cameras because of the load placed upon the computer’s processor.

Typically you won’t see this happen on a security camera system because the processors are made specifically to handle the type of digital processing that digital video requires.  Plus, there are no other high-demand functions for the DVR processor.  When using a USB security camera on a computer it may require so much of the computer’s resources that the computer can do nothing else (like check e-mail for example).

So in conclusion the choice is yours.  Purchase a complete system with cameras, DVR, etc. or go the cheaper route and purchase a USB security camera which could consume your computer during use.

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Vandal Proof Security Camera

Written By:
Thursday, September 8th, 2011

Vandal proof security cameras are excellent for mounting in areas where the security digital video camera might otherwise be tampered with.  Although they may not be able to sustain the injury inflicted upon them with something like a hard swing from a baseball bat, they are built with “vandal-proofing” technology in mind.

There are basically three types of digital video security and surveillance cameras:  1. The box camera; 2. The bullet camera; and, 3. The dome camera.  THe box and the bullet cameras, mainly because of the way they are mounted, are fairly easy to tamper with.  Especially the bullet camera, it can easily be persuaded to move on its mount thereby re-aiming the camera in a totally different direction and field of view.

The fact that the cameras are often even used for monitoring vandalism is a serious and often forgotten situation.  Therefore, the very essence of fighting vandalism becomes the specific target once the camera is installed.  After all, the vandal proof security camera is one of the most visible components of the entire security and surveillance system.  If the system (specifically the camera) is installed properly, it will be in the hot spot which is the area of highest vandalism occurrence.

To combat vandalism, consider exactly what you are trying to monitor or catch on camera and mount the camera accordingly, to make that the camera’s field of view.  However, if possible there are some things you can do to help prevent vandalism of the camera.  For example, a camera may normally be mounted (arbitrarily) at about 8 feet.  At this height the camera is too vulnerable.  If possible, consider the multiple angles of view to the same field of vision and see if there is a possibility of mounting the camera at 15 feet or more.  This should place the camera out of jumping distance of most would-be vandals.

In addition, use a vandal proof security camera.  Security Camera King offers several different models of vandal proof security cameras.  In fact, most of their bundled systems come with either product# OD-LX420IR50 or for the Ultimate series product# OD-LX550IR50; both are vandal proof security cameras.

These models possess certain characteristics in order to reinforce anti-vandalism.  For example the dome camera is mounted flush to the ceiling or wall with the necessary cabling coming into the camera from behind the cameras through the wall.  This means no exposed power supply or video transmission cable that can be readily seen from outside of the camera and subject to being tampered with.

These vandal proof security cameras are constructed of tough metal exterior housings.  These housings are designed to take a beating.  If the camera is mounted properly, it’s going take a very tough object to cause damage to it.

Not only are they inside a metal housing, but the structure of the housing is made so that once the camera is mounted, any visible screws are kept to a minimum as well.  The vandal proof security dome camera is also very “tight” in design; nothing is sticking or hanging out.  This also helps to deter vandalism.

Another feature of the vandal proof security camera is the clear shield which the lens is placed behind. A camera’s vulnerability to vandals is probably its lens.  The lens has to function (be aimed at the proper field of vision) but simultaneously be protected somehow so as not to interfere with its function.

Therefore to provide the greatest protection to the lens the clear shield on a vandal proof security camera is usually made from Lexan®, chemically known as polycarbonate resin thermoplastic.  You may not be familiar with the chemical name “polycarbonate resin thermoplastic” and you may not even be familiar with its registered trademark name, “Lexan®,” but you certainly are familiar with some of its uses.  Lexan is commonly used in space and sports helmets, clear high performance windshields and aircraft canopies, and bullet proof windows.

These features are generally unique to the vandal proof security camera.   In addition to these extra features with careful consideration concerning mounting you can easily keep and maintain a good working vandal proof security camera for years.

If you have any more questions about vandal proof security cameras please contact one of Security Camera King’s security experts via on-line “Live Chat” or telephone at 866-573-8878 Monday through Friday from 9AM to 6PM EST.

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Security Camera Online

Written By:
Friday, August 26th, 2011

It hasn’t been that long since we have had the advantage of using a security camera online. Before the proliferation of the Internet, security cameras at best, sent their images wirelessly using a radio frequency transmitter to repeaters (receiver/transmitters that would keep the signal viable and pass it along to its destination) or directly to a nearby monitoring company.

The inability to use a security camera online made monitoring somewhat tedious. Monitoring company locations were restricted as to their location in order that they remain close to the general area of their clients. Today, using a security camera online, the client’s camera system could be located in the state of Washington and the monitoring could be conducted in Florida.

In fact Security Camera King’s sister service, Digital Security Guard does just that. This professional monitoring service can be provided for just about any online system in the world.  As for Digital Security Guard, their service is available 24 hours a day, 7 days a week, and 365 days a year. Their nationally licensed trained guards follow your instructions exactly should a security breach occur.

If using a professional monitoring company doesn’t work for you, then perhaps you would like to monitor your system yourself or have an employee perform the job. This is all possible thanks to the technology advancement of having a security camera online.

But just exactly how do you get a security camera online? There are two basic methods that can be used to get a security camera online. One way is to use IP ready cameras. IP is the acronym, Internet Protocol, and these cameras have their own web server technology so they can be connected directly to the Internet.

Once connected, their video “transmission” is via the Internet and they can be accessed using any normal Web browser and a personal computer or Smartphone. These cameras can also connect to a Network Video Recorder or NVR for recording the video images. This means that in many cases, a store owner for example, may own two different convenient stores within a city that are several miles apart. Using IP ready cameras he can view both of them at the same time and record them to the NVR if desired as well.

This is made possible by programming utilities called CODECs, short for COmpression/DECompression utility. The object of a CODEC is to reduce the size of the file while maintaining a high quality video image. But, they can also be used for purposes such as preparing a streaming file that can be sent over the Internet for real-time (live) monitoring. Many IP ready cameras use two CODECs. For example one CODEC MJPEG will be used to compress the file for saving on the NVR’s hard disk drive and the other CODEC H.264 (the latest, most efficient CODEC) for streaming throughout the Internet for real time viewing using an Internet browser and personal computer.

The other method for getting a security camera online is by using a Digital Video Recorder or DVR that has its own Web server technology and is IP ready. The DVR is connected to a broad band Internet connection while the cameras are connected to the DVR in the conventional method, such as using RG59 coaxial cable.

The key here is that the camera does not directly connect to the Internet. Instead the DVR remains the communication center for the entire system and it’s the DVR that makes the cameras visible via the Internet. As a matter of fact, even Pan-Tilt-Zoom (PTZ) cameras can be controlled this way and not only by personal computer but also by Smartphone.

So if you are considering the purchase of a security camera online system and are uncertain as to what method to use, contact one of our security experts today and they will be glad to help you decide which type is best for your situation.

Our security experts can be reached via on-line “Live Chat” or by telephone at 866-573-8878 Monday thru Friday from 9AM to 6PM EST. Be ready to tell them why you want a security camera online, what kind of physical layout you would like to cover, if you want to record the video image and/or do you want a professional monitoring company to do that for you.

Also tell them how you will access the system (directly, personal computer, or smartphone) and wheat your budget is for your system. They will find a security camera online system that will be tailor made for you!

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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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