Posts Tagged ‘ charged coupled device’



Quality Outdoor Security Cameras

Written By:
Tuesday, July 13th, 2010

There’s nothing like a security and surveillance system with quality outdoor security cameras. A good quality camera is rugged and well protected from the elements, yet sensitive enough in function to produce a video image with only the slightest amount of light. Quality outdoor security cameras need to be maintenance free as well, since these cameras are often mounted high atop poles, buildings or other difficult to reach locations.

Outdoor security cameras are built with a protective case or enclosure that protects the camera from various types of debris and other matter. This is necessary because these cameras are often mounted in open locations that expose them to heavy winds, rain, snow, and dirt and dust. High quality outdoor security cameras are normally rated according to the protection the camera is afforded by the covering using an International Electrical code standard. The standard provides criteria for a rating called an Ingress Protection code or rating.

The ingress protection code is designated by the letters IP followed by two digits. The first digit corresponds to dry matter objects; the larger the number the smaller the matter that is prevented from entering the camera. The second digit corresponds to liquid. Quality outdoor security cameras should be IP rated and their rating should be at least an IP66 or IP67. Both ratings’ first digit (the numeral “6”) indicates that the camera is dust tight; no dust can enter the camera. An outdoor camera with an IP66 rating can also withstand powerful jets of water from any direction. An outdoor camera with an IP67 rating can also withstand being submerged in water up to one meter in depth.

When purchasing quality outdoor security cameras another key component to consider is the image sensing chip. Not all chips are made alike so it is important that your camera uses a quality manufacturer’s sensor chip. There are two different types of sensor chips. Both are electrical circuits that contain material that is sensitive to light. When the lens focuses the light image on the chip, the chip is able to convert the light energy into electrical energy which can then create a digital picture.

The two types of sensor chips are called either a Charged Coupled Device or CCD or a Complimentary Metal Oxide Semiconductor. Each of these sensors works a little differently but both still produce the same result; a digital video image. Not only should you look for sensor chips built by quality manufacturers but the size of the chip can be important too. CCDs and CMOSs normally range in size from about ¼ inch to up to 1 inch or more. Generally the larger the size of the chip the larger the size of the video produced and the greater the resolution or clarity.

Probably one of the most popular quality sensor chips used in many quality outdoor security cameras is the Sony 1/3 inch Super HAD II CCD. This is not the only quality sensor ship available of course, but it is very popular. This chip produces video resolution of at least 420 TV lines and is capable of producing video with up to 600 TV lines of resolution. This chip is also used in night vision infrared cameras as well.

Another characteristic to look for in quality outdoor security cameras is called the signal to noise ratio. It is normally written in the cameras specifications as “S/N.” The higher this number is, the clearer the picture produced by the camera. A good quality camera will have a minimum S/N ratio of 48dB, although there are cameras that have rations as high as 60 dB or higher.

High quality outdoor security cameras should also be accompanied with good quality service and support. Look for camera vendors that offer free technical support for installation and setup of your cameras. In addition, vendors should service the products that they sell.

Finally, quality outdoor security cameras should be rugged enough to last for years once they are mounted and installed and really should require no maintenance. However, look for cameras that have good, comprehensive warranties. A good warranty for an outdoor digital video camera will cover a period of at least 1 year but better warranties will offer 3 years of coverage.

Remember when shopping for your quality outdoor security camera that there are several characteristics of the cameras to look for and the cameras should come with service and support. A good quality outdoor security camera will provide you with years of satisfying service.

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CCTV Video Security Surveillance Equipment

Written By:
Friday, May 28th, 2010

CCTV video security surveillance equipment or closed circuit television video security surveillance equipment can provide all of your security and monitoring needs. Contemporary CCTV video security surveillance equipment offers several features and great versatility along with affordable prices that make this equipment and excellent choice for business and residential applications.

CCTV video security surveillance equipment consists of a few basic components that make up the security systems. Each of these components offers convenient and often highly technologically advanced features that create the versatility of the system such that the equipment can be used for nearly any situation or application. In addition, there are several additional components that can be added to a basic system with ease.

Basic CCTV video security surveillance equipment consists of the following five items:

  • Digital video camera(s)
  • A processor or capture board
  • A monitor
  • A digital video recorder or DVR

Probably the most important component is the digital video camera. Digital cameras for CCTV video security surveillance come in a variety of types, sizes, and functions. Cameras can be classed as either indoor or outdoor cameras. The major difference between the two is that outdoor cameras are built within a casing or enclosure that protects the sensitive electronic components of the camera from the weather and other environmental elements.

These cameras often contain an International Electrical standard code rating that provides the user with a description of the ability of the camera to withstand penetration by liquids and particles. This rating known as an Ingress Protection code or IP code is normally an IP66 or an IP67 for an outdoor CCTV video security camera. IP66 means that the camera is impervious to dust and that powerful water jets from any direction shall have no harmful effects. A rating of IP67 means the camera is impervious to dust and can be submerged in water up to 1 meter in depth.

CCTV video security surveillance equipment cameras can be purchased with other specialized features. Most of these features are based upon recent technological innovations and may increase the cost of the camera depending on the feature and its range of function but are well worth the expense.

For example, most CCTV video cameras create video using a small sensor chip called a Charged Coupled Device or CCD. The CCD converts the light transmitted through the camera lens into an electrical charge that can be detected and used to create high quality digital video. Some CCDs are so sensitive that they can produce high quality video with very little visible light. These cameras, are called day/night vision cameras. Other cameras, called Infrared (IR) night vision cameras can produce a high quality color image when there is visible light present and can produce a high quality monochromatic or black and white image under total darkness conditions when absolutely no visible light is present.

Other features that can be included on CCTV video cameras include a pan, tilt, and/or zoom function, the ability to record audio, and the ability to transmit the video signal from the camera to a receiver using radio waves.

Pan and tilt functions permit the camera to be moved in different directions allowing the camera to cover a wider area of view than one that is stationary. Using pan and tilt functions, one camera may be able to cover the area that may take two or three stationary areas to cover. The zoom function also allows the camera to take advantage of enlarging the field of view, much like a telephoto lens. Cameras can be purchased with the individual pan, tilt, and zoom functions or they can be offered collectively, often referred to as PTZ cameras.

PTZ cameras can be controlled manually, by remote control, and by programming. Programming functions for PTZ cameras can provide automatic tracking functions when utilized with automatic motion detection. For example, the camera can follow a car traveling through a parking lot or an individual in a specific area.
Wireless CCTV video security surveillance equipment normally uses the 2.8 MHz or 5.8 MHz radio band to transmit the video image from the camera to the receiver, which then sends it along to the processor. Cameras come with built-in antennas and circuitry that send the images.

CCTV video security surveillance equipment has seen tremendous technological improvements in just the past few years making the equipment versatile and affordable for just about any application.

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40 Color Night Vision Security Camera

Written By:
Thursday, May 6th, 2010

Thanks to relatively recent technological advances in electronic imaging, night vision security cameras are becoming one of the most popular types of security/surveillance cameras for businesses and residences alike. Before purchasing a night vision security camera it’s important that you are familiar with some of the terminology and functions associated with this specialized type of security system.

Most Closed Circuit Television or CCTV cameras today are digital cameras. Basically, they take pictures or video much the same way as a personal digital camera or camcorder. These cameras operate by allowing light to penetrate through an iris or variable opening, a lens, and then strike a charged coupled device or CCD.

The iris is basically like the pupil of an eyeball; when there is too much light the iris makes the opening in the lens very small so as not to “flood” the CCD with light. When there is very little or no light, such is the case for night vision security cameras, the iris is at its maximum opening to allow as much available light as possible to strike the CCD.

The chief purpose of the lens is to keep an image at a certain distance in focus. Various lens sizes can be used to achieve focus ranges from just a few feet to several hundred. If the lens is rated with an “F-Stop” the lower the number for night vision purposes is better because it means it does not absorb much of the light passing through it.

The key to a night vision security camera is the CCD. CCDs work by converting light into electrons. These electrons have a charge which can be monitored and used to produce a digital image. Most CCDs are inherently sensitive to infrared (IR) radiation. This means that they require no special treatment to produce images using infrared radiation.

There are basically two types of security cameras used as night vision security cameras. It’s important to understand the difference between the two. One type is also called a day/night camera and the other is an IR camera.

Day/night cameras produce color images when sufficient light is present. These cameras have very sensitive CCDs that allow the camera to process light into an image at very low light intensity. Light intensity is normally measured in units called LUX. In full daylight (but not direct sunlight) an average LUX reading ranges from 10,000 to 25,000 LUX. By contrast, a full moon on a clear night in non-tropical geographical locations produces about .27 LUX. Many day/night cameras can produce clear images at less than 1 LUX. In fact some day/night vision security cameras’ specifications indicate sensitivities as low as .0014 LUX or less. However, day/night cameras must have some available light to produce an image. They cannot produce an image in total darkness or 0 LUX.

Night vision security cameras that can produce images in 0 LUX or no-light conditions are infrared cameras. These cameras can “see” infrared radiation in the 700 – 1400 nanometer wavelength range known as “near infrared.” The human eye cannot see this wavelength of electromagnetic radiation so any “near infrared” light is virtually invisible to our eyes.

Night vision security cameras using IR technology illuminate their target area with infrared light. This light is provided by light emitting diodes or LEDs that are placed around the lens of the camera. The stronger the LEDs and the greater number of LEDs placed around the camera lens determines the effective range and field of vision of IR cameras. In essence, the LEDs are actually providing a spotlight on the target area but because the light is the near infrared type we cannot see it.

Night vision security cameras using IR technology produce a black and white or monochromatic image. This radiation is outside the visible color spectrum therefore the images are not in color. However, the clarity and contrast is just as sharp as normal color images. Also, the range of the infrared night vision security camera is limited by the infrared light produced by the LEDs. Most premium IR cameras have an effective operating range of up to about 150 feet. It’s imperative to know the specification for IR range when purchasing an IR camera as a camera with a very short range would be useless for monitoring an area 100 feet from the camera.

Knowing a little about the two types of night vision security camera can help you make the right choice for your needs.

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