Posts Tagged ‘ cmos’



Wireless Spy Camera

Written By:
Wednesday, November 17th, 2010

There are times when covert digital video monitoring is needed and nothing can fulfill your security and surveillance needs like wireless spy cameras from Security Camera King. We offer a full line of wireless spy cameras that maintain their concealed identity, transmit their video images without the need for wire hook-ups, and produce high resolution digital video.

Digital video security and surveillance monitoring can be classified into two different types based on whether the monitoring is obvious or purposely intended to be concealed. In the security video industry, these two categories are often referred to as covert (meaning hidden, stealthy, or concealed) and overt (meaning obvious, open, or unconcealed). Covert cameras that broadcast their digital video using radio signals are often referred to as wireless spy cameras.

Wireless spy cameras can be classified into two different types as well based on how the camera achieves being overt. Wireless spy cameras do this by either being incredibly small or disguised as some other object other than a security camera (or some cameras may use a combination of both). The incredibly small types of cameras are often referred to as pinhole type cameras and these are often designed to be disguised as very small objects as well. In order to understand how this is possible, let’s take a look at an incredibly small wireless spy camera and see how it works.

Digital video cameras work by focusing light images on a sensor that can transfer the light energy of the image into electrical energy. There are two different sensors that may be used for this purpose; a Charged Coupled Device or CCD or a Complimentary Metal Oxide Semiconductor or CMOS.

Each sensor performs the same task (transfers light energy into electrical energy that can be measured) but goes about it in a slightly different way. Typically, CCDs have provided a higher quality picture while CMOSs use much less electricity to operate. However, as electronic technology advances both are producing high resolution video images with a minimal amount of power needed to do the job.

These sensor chips, usually in the shape of a square, can be very small, as small as only 1/4″. Today’s electronic technology can produce incredibly small Integrated Circuit or IC chips that house the circuitry for processing video images, converting them to radio signals, and transmitting them to a receiver. Advanced lens physics and manufacture can produce a small wide-angle lens as small as 3.7 mm for example. Combine all three of these technologies and you could produce a wireless spy camera as small as the head of a screw or a button that produce high quality video images. In fact, Security Camera King carries two such cameras, our 2.4 GHz wireless button camera and our 2.4 GHz wireless screw camera.

Wireless spy cameras labeled as “2.4 GHz” refer to the technology that is used to transmit the wireless signal. A 2.4 GHz wireless spy camera uses the same high-quality dependable technology to transmit its radio signals as many land line based wireless telephones. The transmitter and receiver are tuned to a frequency in the 2.4 GHz radio wave spectrum.

The term “wireless spy camera” may impart a connotation of negativity associated with its name. It’s important to note that wireless spy cameras are not necessarily used for this purpose but may be used for the sake of aesthetics in appearance. Our 2.4 GHz Wireless Dog Baby Monitor Camera is a fine example.

Some wireless spy cameras may be used as standalone monitor systems. That is, the camera/transmitter unit comes with its own receiver/monitor. These units are usually designed for monitoring and not recording so although they may come with their own portable, handheld LCD monitor, they often do not record. Our wireless dog baby monitor camera is a good example of this; typically it is not necessary to record baby monitor transmissions.

Other cameras may be designed to use with a standalone video security system that includes a DVR   for storing video. These cameras may or may not come with a receiver, so it’s important that you check on this in the camera’s description or specifications area.

Sometimes the greatest advantage of using digital video security cameras is the ability to monitor and record activities without any indication that video monitoring is occurring and Security Camera Kings wireless spy cameras do just that. Check out our vast selection by clicking on “Security Cameras” then “Wireless Hidden Cameras” on the left side of our web page.

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640 x 480 Infrared Camera

Written By:
Monday, October 11th, 2010

What exactly is a 640 x 480 infrared camera? This can be a complicated answer for many reasons. In the following article we will attempt to address some of the characteristics that can make this seemingly simple question so complicated. Specifically, we will briefly discuss infrared technology and the reference to display resolution and how they relate to a 640 x 480 infrared camera.

First lets discuss the meaning of “infrared” when we talk about a 640 x 480 infrared camera. The term “infrared” refers to the wavelength of electromagnetic radiation. The wavelength of infrared radiation generally ranges between 0.7 and 300 micrometers abbreviated as “µm.” The exact range and categories defined may vary slightly depending on the scale that is used to describe the radiation.

For our purposes, it is sufficient enough to know that infrared radiation is a longer wavelength than visible light, therefore the human eye cannot see it. Further, there may be several categories of infrared radiation based on wavelength but we will only consider two; “near infrared” radiation which is invisible to the human eye but is the closest in wavelength to radiation that is visible to the human eye) and “long-wavelength” also called “far infrared,” which for our discussion is the thermal imaging region which is naturally emitted by objects and requires no external or artificial illumination.

So, on this basis there are essentially two types of 640 x 480 infrared cameras. The first type, and the one most commonly used in digital video security camera systems, is the near infrared camera. This camera contains one of two electronic sensor chips, either a Charged Coupled Device (CCD) or a Complimentary Metal Oxide Semiconductor (CMOS). These sensors are able to convert the light energy into electrical energy that can be measured, thereby creating a digital image. Fortuitously, these sensors inherently detect near infrared radiation as well.

The near infrared 640 x 480 camera uses external infrared radiation (or infrared light) to illuminate the area in its field of view. These cameras use InfraRed Light Emitting Diodes or IR LEDS to illuminate the target area in order to create an image. The IR LEDs are normally configured in an array that surrounds the camera lens so that they are focused in the same direction. However, some cameras may have IR LEDs clustered off to the side of the lens and there are even separate “illuminators” that contain nothing but IR LEDs and can be mounted and aimed separately from the camera.

These cameras normally produce a color image in visible light conditions and when the visible light is not bright enough to produce a high quality video image, they switch to infrared, producing a monochromatic or black and white video image.

The far infrared 640 x 480 infrared camera does not require additional external infrared illumination. This camera uses an infrared “Focal Plane Array” or FPA sensor and is capable of creating a digital video image based solely on the thermal emissions or “heat signatures” of objects. These cameras are often called “Forward Looking InfraRed” or FLIR cameras. These cameras are also often made in a “hand held” version. Older models of these cameras had to be cooled somehow to prevent the users’ and their own thermal emissions from interfering with the image.

Far infrared 640 x 480 infrared cameras are often used not only for covert surveillance and security, but by inspectors and engineers to detect a variety of heat signatures. These cameras can be used to detect areas of heat “leakage” from a building or “hot spots” on mechanical engines and other devices.

As for the reference of “640 x 480″ in a 640 x 480 infrared camera, this refers to the image resolution in pixels that the camera is capable of displaying. Far infrared cameras are more commonly referred to by their resolution in pixels, i.e. 640 x 480 infrared camera. However, digital video security cameras may also use the same description.

This can be confusing because older, analog security video cameras more commonly referred to their resolution in terms of TVL or Television Lines. Since the security camera industry today uses primarily digital video cameras, they may refer to the resolution in terms of TVL or pixels.

Perhaps the easiest way to tell the difference between the two is the price. Near infrared digital image security video cameras can be purchased for as low as less than one hundered while far infrared FLIR cameras range from one to several thousand dollars.


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Wireless Security Camera with Recorder

Written By:
Wednesday, October 6th, 2010

A wireless security camera with recorder can be your answer to an easy to install and easy to operate security device. Technological advancements in electronic components and computer development have made a wireless security camera with recorder a reliable security device that is reasonably priced to fit just about any budget. Use more than one wireless camera with a recorder and you can create your own total coverage wireless security system.

Digital video security systems are becoming extremely popular these days for business use as well as in the home. In addition, there are so many features and/or options available that these systems can be placed just about anywhere for any application.

In this article, we’ll briefly describe a standard digital video security camera system and then elaborate on the differences between it and a wireless security camera system. Finally, we’ll list some of the features and/or options that are available for a wireless security camera with recorder.

A standard digital video security camera with recorder system is a component system that consists of one to many cameras, a Digital Video Recorder or DVR, and a monitor. The system operates with the camera “capturing” digital video and sending it to the DVR (which normally includes a processor as well). The processor creates a digital video file which is stored on the DVR and can be viewed immediately (live) or at a later convenient time.

The standard digital video camera contains one of two sensor chips that convert light energy into measurable electrical energy that can be used to create a video image. The lenses focus the field of view of the camera on these sensors. The chips are the Charged Coupled Device or CCD and the Complimentary Metal Oxide Semiconductor or CMOS.

After the sensor chips have created electrical data that can be used to create a digital video file, they send this data to the DVR and processor via a video transmission cable, usually an RG-59 coaxial cable. Each camera must be connected to a separate cable that is run from the camera to the DVR/processor. The processor than performs the necessary work required to convert the electrical data into a digital video file.

The processor is much like the processor in a personal computer, however security camera systems processors are highly specialized processors that are made to perform specific tasks necessary for digital video security systems. One important task of the processor is to reduce the size of the incredibly large digital video file without sacrificing the quality of the video. It does this by using a COmpression/DECompression or CODEC utility. Once the processor creates the digital video file it can be viewed on a monitor or stored on the DVR for archiving or to be viewed at a later time.

A wireless security camera with recorder system is operates in basically the same manner. The major difference with this system is that the wireless security camera does not use a coaxial video transmission cable to send the video data to the recorder. Instead, it converts the data into radio signals and sends the data as a radio wave to a receiver which is connected to the recorder.

There are a few variations on how the camera prepares and sends its wireless data. The most common method is for the camera to have an on-board transmitter and antenna that transmits a radio signal to a corresponding receiver. Many different radio frequencies and technologies are used, but the most common is the 2.4 or 5.8 GHz band technology. This is the same sort of wireless technology used on land based wireless telephones. Once the receiver accepts the signal it passes it on to the DVR/processor via a wired connection.

Another type of wireless camera is the Internet Protocol ready or IP ready wireless camera. This camera has its own web server technology that allows it to be connected directly to the internet. It normally connects wirelessly to the internet by sending its signals to your broadband wireless modem or router. The recorder can be connected anywhere there is internet access.

There are many features/options available for a wireless security camera with recorder. Here is a partial list:

  • • Indoor/outdoor cameras
  • • Day/night/infrared vision cameras
  • • Pan-Tilt-Zoom (PTZ) cameras
  • • Audio recording
  • • Battery (rechargeable) powered cameras
  • • Hidden/disguised covert surveillance cameras

This should give you some basic information about how a wireless security camera with recorder works and some the optional features that are available.

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Infrared Digital Camera Lens

Written By:
Wednesday, September 29th, 2010

Do security cameras need infrared digital camera lenses to produce infrared video images? How does an digital video infrared camera produce infrared images?

Before we attempt to answer any of these questions, let’s discuss how digital video security cameras work to fully understand their function and how it can relate to infrared image production.

First, a typical contemporary security camera is a digital video camera versus the older legacy analog video cameras. Digital video security cameras are very similar to digital photograph cameras, except that digital video cameras take several digital photographs within a very short time period. On the average, good quality digital video cameras will work at speeds of 30 photographs per second also known as 30 frames per second or 30 fps. Photographs taken at this speed rate, when displayed at the same rate, appear to the human eye as smooth, fluid video.

Digital video security cameras create digital images by using one of two different sensors that transfer light energy into electrical energy that can be measured and used to create a digital video image. One of the sensors is called a Charged Coupled Device or CCD and the other is a Complimentary Metal Oxide Semiconductor or CMOS. These sensor chips are relatively small and for most digital video security cameras range from about 1/4″ to 1 inch in diameter. Generally, but not always, the bigger size of the chip produces a higher resolution image.

The interesting thing about both chips is that they are inherently sensitive to infrared radiation in the near infrared spectrum. No infrared digital camera lens is needed for them to sense near infrared radiation or “light.” This type of infrared radiation is invisible to the human eye however so we cannot detect it. As an example most appliance remote controls (televisions, DVD players, cable TV boxes, etc.) operate by using infrared signals. (Try looking at your remote while pressing a command button – you should see nothing, then look at it again through your digital camera – you should see a flashing white light.

As you can see, your camera is already able to detect near infrared spectrum radiation, so realistically no infrared digital camera lens is required. This is a great value-added feature of the CCD and CMOS sensor chips.

Near infrared radiation is not normally emitted by all objects, i.e. it is not the same wavelength of infrared light that comprises object’s heat signatures. Therefore, your infrared digital video camera needs infrared illumination of the field of view in order for it to produce an image. This is accomplished by using several InfraRed Light Emitting Diodes or IT LEDs to illuminate the field of view. Generally, the more LEDs that are used, the longer the infrared range of the camera.

Therefore it is not necessary to used an infrared digital camera lens to make your digital camera take infrared video images. However, it is necessary for the target area to be illuminated with near infrared spectrum light, so IR LEDs or other infrared illumination is required.

One thing about this business of infrared digital camera lenses and imagery. Security cameras are often marketed as day/night or true day/night cameras, meaning they can take high quality color digital video in visible light conditions and high quality black and white or monochromatic digital video in dark conditions (infrared light does not express “colors.”)

A typical day/night camera uses software or circuitry to filter out the infrared light that it picks up during visible lighting conditions. If it didn’t the extra infrared radiation would combine with visible light to make a lesser quality image. True day/night cameras however, have an internal filter that is used during visible lighting conditions to filter out the infrared light.

This filter is often called an IR Cut Filter (InfraRed Cut-off Filter). It produces a much cleaner, brighter, and higher quality video image. Under infrared conditions, the filter is mechanically removed to allow penetration of infrared light to the sensor. Generally, “true day/night” cameras are more expensive because they contain this filter and the mechanism to remove and replace it.

So as you can see, digital video security cameras by the nature of the electronic sensor they use, can already detect infrared radiation without the need for an infrared digital camera lens. In fact, IR LEDs are more likely needed to create IR light and filters are needed to suppress the infrared radiation during visible light periods to produce a higher quality image.

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Camera Mounted Infrared Illuminator

Written By:
Monday, August 2nd, 2010

A camera mounted infrared illuminator is used with most night vision infrared digital video surveillance and security cameras to provide invisible light that is used to create an infrared digital video. The illuminator is normally aimed in the exact same direction of the camera lens so that it can provide infrared light beams to illuminate the target area. Infrared illumination can be “seen” by the camera, but cannot be seen by the human eye.

Let’s take a closer look at how a night vision infrared digital video security camera works in order to appreciate the need for the camera mounted infrared illuminator.

A night vision infrared digital video security camera can produce high quality color video footage when there is enough visible light present. When there is not enough visible light present or when in total darkness, a sensor on the camera switches it into the infrared mode. Digital video recorded under the infrared mode is high quality video footage as well, but is monochromatic or black and white, since infrared light does not emit color.

These cameras create a video image by using one of two sensors that convert light energy into electrical energy that can be quantified and used to create a digital video picture. The sensors that are normally used are the Charged Coupled Device or CCD, or the Complimentary Metal Oxide Semiconductor or CMOS. The camera lens focuses the light from the image onto the sensor which then converts the light image into an electronic image which can be viewed on a monitor or stored as a digital video file.

Both the CCD and CMOS can be constructed with various sensitivities to light. Some cameras can produce full-color, high quality digital video with as little as .002 lux or less of light. These cameras are usually called day/night vision cameras and still require visible light to operate properly; they are infrared sensitive cameras.

A camera mounted infrared illuminator is required on night vision infrared digital video cameras to provide plenty of “light” to illuminate the subject. However, in this case the light is actually infrared radiation from the near infrared spectrum. This light or radiation has a similar effect as a flood light or spot light would on a normal visible-light digital video camera.

Most camera mounted infrared illuminators are created from several infrared Light Emitting Diodes or LEDs. The LEDs are able to create a sufficient amount of radiation that can be focused in the direction of the camera’s field of view. The advantage of using LEDs is that they use a relatively low amount of electrical energy and are small and compact.

The LEDS are normally arranged in an array that surrounds the outside of the camera’s lens or is in a grouping off to the side of the lens but aimed in the same direction as the camera. Generally the more LEDS used the greater the angle and the longer the distance of the effective infrared field of view. For this reason, every night vision infrared digital video camera has an effective target range.

If you are considering the purchase of an infrared night vision camera, be certain that the camera matches the range that you need for the job. There are a variety of different cameras available based on their effective range. Range values for cameras usually begin around 20 to 30 feet with cameras that have ranges of up to 200 feet or more. Cameras are more expensive for higher ranges, because of the extra LEDs that are used for the camera mounted infrared illuminator.

Some cameras ranges and angle of field of view can be extended by using additional infrared LED illuminators. However, these are not camera mounted infrared illuminators; they are mounted separately on their own and must be manually adjusted to ensure that they are aimed properly at the field of view of the camera.

Camera mounted infrared illuminators are an integral and necessary component of any infrared digital video camera. They supply the infrared “light” or radiation that is needed to illuminate the target area for the camera. Normally, the source for this radiation is an array of infrared LEDs that surround the camera lens or are located on the camera. Additional LED illuminators can also be purchased as accessories.

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