Posts Tagged ‘ infrared radiation ’

Infrared Camera System

Thursday, September 15th, 2011

If you need security and surveillance coverage in poorly lit or no light areas, you should try using an infrared camera system.  In the following article we’ll talk about how these cameras work and what to look (out) for when purchasing a system.

Under normal daylight conditions a digital video security camera utilizes the light waves that are reflected from the objects in its field of vision.  It does this by using a lens to focus the entire image onto a sensor chip that is usually 1/4 or 1/3 of an inch square.  The sensor chips work by converting the light energy into a small electrical impulse which can be measured and therefore ultimately used to create a digital video image.

Although both chips work a little differently, each produces the same result.  The type of sensor used is usually the choice of the manufacturer.  They are normally referred to by an acronym because the names are relatively long.

One sensor is called a Charged Coupled Device or CCD and the other is called a Complementary Metal Oxide Semiconductor or CMOS.  These sensors have a lot in common even though they function differently.  However one of their common traits is that both the CCD and the CMOS inherently sense infrared waves in the near infrared spectrum.  Because of this, a regular digital video camera can also be used as an infrared camera or collectively as an infrared camera system.

Actually, in some systems, a filter is used during the daytime to prevent infrared radiation from reaching the sensor.  Sometimes extra infrared in addition to visible light exposure may result in a poor daytime image without a filter.

A typical infrared camera system also produces images that are either black and white or monochromatic.  Even though these images may not be “in color” they can still maintain the crisp, clear, high-resolution that is associated with the daytime use of the cameras.

An infrared camera system does not produce color images when working in infrared mode because it senses the near infrared spectrum.  The near infrared spectrum does not include visible light so only a monochromatic image, not a color image, is seen.  Some may consider this a disadvantage of infrared camera systems, but to many the other special features of an infrared camera far out weigh this particular feature.

One advantage of using infrared radiation in darkness is that the human eye can not see the infrared radiation (light)–but the camera can.  This feature can put the camera in a stealth mode making it very difficult to see at night, yet its picture is just as clear and detailed as if it were daylight conditions.

The near infrared light spectrum is at the lower end of the infrared scale so it generally requires artificial near infrared light to do its job.  But where does the infrared camera system get its infrared light?

Basically, of the three types of cameras box, bullet, and dome, the bullet and dome cameras may furnish their own light.  This is done by placing InfraRed Light Emitting Diodes or IR LEDs in an array around the camera lens.  Although humans can’t see this special light source, it provides enough light as to make it look like a floodlight was used to capture the video image.

Generally, the more IR LEDs that are used the longer the range of the infrared video image from the camera.  One thing to look (out) for is the IR range.  If you are interested in purchasing an infrared camera system, you need to measure the distance you want the camera to cover under IR mode.  Most cameras state this on their package in their specifications for example, “IR Range 60 feet indoors 50 feet outdoors.”

If the infrared camera system does not achieve the distance you may require, you can either purchase a camera with a longer range or purchase an “Illuminator.”  An illuminator is a series of IR LEDs that at are strong enough to shed infrared “light” up to 300 feet or more.  Illuminators often mount like cameras and use the same power requirements of a typical camera.  Once again, check the specifications of illuminator to make sure the range extension it provides meets your requirements.

If you have any additional questions about an infrared camera system, please contact one of Security Camera King’s security experts by Live Chat or telephone.  We love to help!



Motion Activated Wireless Security Camera

Monday, October 18th, 2010

Here are some common questions we’ve had about motion activated wireless security cameras:
• How do these cameras detect motion?
• How does the wireless function work and why would I need it?
• What provides the power for this camera?
• Can I install this camera myself?
• Does this camera produce color or black and white video?
• How do I record the video from a motion activated wireless security camera?

In the following article we will answer these questions and provide you with some general background knowledge concerning a motion activated wireless security camera.

A motion activated wireless security camera is a digital video camera that contains a built in motion detector. When the motion detector senses motion, it turns the video camera on so that it may begin recording digital video images. This means that the camera is only recording video images when the motion detector senses movement.

The motion sensor itself is an infrared sensor. In fact, the name of the sensor is a Passive InfraRed or PIR detector. It works by constantly monitoring the infrared radiation (IR) in the cameras general field of view. When a sudden change in this radiation occurs, the sensor can detect it, and assumes it is caused by an object in motion. The PIR motion sensor is connected to a relay switch so that when motion is connected, the relay switch turns on the camera to being recording. The recording session ends when either the motion has stopped or after a pre-programmed period of time after the motion has stopped.

Digital video images are basically the same thing as digital photographs however they are taken very rapidly in succession. High quality fluid motion is created by taking up to 30 photographs (in video talk these are called “Frames”) per second or 30 FPS. Digital video then is basically many (on the average depending upon the total length of recording time) several thousand to hundred thousand photographs. Imagine the size of a data file for one high quality digital photograph. Now multiply that times 300,000 for example, and that’s how large the digital video file could be.

A digital video camera running constantly at 30 FPS, that creates 1 Megabyte(MB) of data for every frame, creates 30 MB per second or 1.8 Gigabytes (GB) per minute or 108 GB per hour. Using one camera constantly with a 500 GB Digital video Recorder or DVR, would use up all the disk storage space in less than 5 hours recording time.

A motion activated wireless security camera however, only records video when motion is detected. When used properly, this greatly reduces the size of the digital files and conserves DVR storage space.

A second benefit of using a motion activated wireless security camera is power conservation. A motion activated wireless security camera may not be totally wireless. Although these cameras use radio signals to send their video data to a receiver of DVR, they still must be supplied with low voltage Direct Current (DC) power. This is usually accomplished by using a power distribution center and running a small wire from it to each camera or by using a plug-in outlet transformer and running a wire from it to the camera(s).

However, there is a third option for providing electrical power to the camera as well. Some cameras can utilize rechargeable batteries. These cameras use very little power for the constant “on” state of the PIR sensor. The greatest power drain on the system is when the camera is actively recording. Therefore a motion activated wireless security camera can also greatly conserve on power consumption and therefore extend rechargeable battery usage periods, another great benefit of this type of camera.

The camera is easy to install and operate so any “do-it-your-selfer” can install and operate the camera. Once the camera is mounted, and the system is set up, the camera will automatically begin functioning, sending digital video data to the DVR so that the video data can be stored on the hard disk drive.

A motion activated wireless security camera has many other features and options that make it a powerfully versatile security tool. In addition, the camera can record in black and white or high quality color.

This should provide you with some basic knowledge about a motion activated wireless security camera. If you have any addition questions or would like to purchase a camera or system, please contact one of Security Camera Kings security experts today.