Posts Tagged ‘ night vision’



Night Vision Wireless Security Camera

Written By:
Tuesday, January 25th, 2011

Tired of not being able to see things that go “bump” in the dark? If that’s the case, you need a night vision wireless security camera. These cameras take advantage of the latest technology in digital camera security systems, are easy to install, and are reasonably priced as well.

Can a night vision wireless security camera actually “see” in the dark? Well, indirectly the answer is yes. Although the camera doesn’t actually “see” in the dark, it uses infrared illumination to light the target area of the camera. This infrared illumination is actually invisible to the human eye, so we can’t see it, but the camera can. Before we get ahead of ourselves let’s back up and start at the beginning.

There are many types of digital video security cameras based on appearance and function. The night vision wireless security camera is one of those types that contains highly specialized features for highly specialized applications. Some of the other optional features that are available include the following:

• Pan-Tilt-Zoom or PTZ. This feature allows the camera to move “left and right” and “up and down” which greatly increases the field of vision of the camera. This camera can also “zoom in” on objects to enlarge their view.
• Motion Detection. Camera can come equipped with motion detectors that turn the camera recording on only when motion is detected.
• Audio Recording. Sounds can also be recorded as well as conducting two-way audio communication.
• Internet Protocol or IP ready. Cameras can connect to and use the Internet for networking.

Let’s keep the “focus” (pun intended) on a night vision wireless security camera. First, the camera operates by transferring light images into electronic impulses that can be measured to create digital video images. In digital video language, this transferring of images is normally referred to as “capturing.”

The night vision wireless security camera captures images by using a very special electronic sensor. There are actually two different types of sensors and although they capture images in a slightly different way, they both produce the same end result (a digital video image.) One of the sensors is a Charged Coupled Device or CCD and the other is a Complimentary Metal Oxide Semiconductor or CMOS.

It just so happens, that both CCDs and CMOSs are inherently sensitive to not only the spectrum of electromagnetic radiation we call “visible light” but are also sensitive to infrared radiation or “invisible infrared light.” (We call it invisible because as mentioned earlier, the human eye cannot see it.) Specifically, most night vision wireless security cameras are inherently sensitive to a band of infrared radiation called “near infrared radiation” or for our purpose, we’ll call infrared illumination.

So where does the infrared illumination originate? There are some small amounts that are emitted (or radiated) from objects, especially heat and light sources. However, a night vision wireless security camera normally provides its own illumination using an array of infrared Light Emitting Diodes or LEDs that surround the camera lens or are right next to it pointing in the direction of the camera’s field of vision.

The infrared LEDs use much less electricity than a typical filament light, and the illumination they emit can’t be seen by humans but can be detected by the night vision wireless security camera. There are some camera/systems that do not include LEDs around the lens but may use separate infrared LED “illuminators.” These illuminators can also be used with cameras that do already have LEDs to extend their range.

This brings us to an important point. Since the LEDs provide the illumination for the night vision wireless security camera, every camera has a range. Be certain before purchasing your camera that you know what range you will require and that the camera you are purchasing can capture images within that range.

Finally, as the name indicates, a night vision wireless security camera does not require a video transmission cable to be run from each camera to the DVR as other non-wireless systems do. The camera takes advantage of one of many different types of wireless technologies to send its images via radio waves to a receiver or a DVR with a built-in receiver. One example of this technology is 2.4 or 5.8 MHz technology; the same used for wireless land-line based telephones. Talk about making installation easy!

Contact one of our security experts via our on-line “Live Chat” or via telephone if you have any additional questions concerning a night vision wireless security camera.

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Wireless Night Vision Outdoor Security Camera

Written By:
Tuesday, June 1st, 2010

A wireless night vision outdoor security camera is a digital video camera with highly specialized features. Modern technological advancements have made these specialized features available at a very affordable price while offering high quality video images.

Outdoor security cameras differ from their counterparts the indoor security cameras, in that they are enclosed in a case that protects them from weather and environmental elements. Wireless night vision outdoor security cameras are often rated according to the protection that they offer. This protection is often described using an International Electrical Code standard called an Ingress Protection rating, International Protection Rating, or IP code. Most wireless night vision outdoor security cameras have an IP code of IP66 or IP67. IP66 means that the camera is dust tight and that water from powerful jets in any direction will have no harmful effects on the camera. IP67 means that the camera is dust tight and can withstand being submerged in water up to 1 meter in depth.

Digital video security cameras create images by using one of two special electronic sensor chips. Some digital security cameras use a Complimentary Metal Oxide Semiconductor or CMOS chip to create high quality color video images. Most wireless night vision outdoor security cameras use a Charged Coupled Device or CCD to create high quality color video using available visible light and high quality monochromatic or black and white video images using infrared (IR) radiation.

CCDs are highly sensitive to light energy known as photons. The CCD is able to transfer light energy into electrical energy in a somewhat similar process that a solar cell transfers sunlight into electricity. The electrical energy created by the CCD can be measured and digitally manipulated to create a video image. This is how a wireless night vision outdoor security camera creates high quality video in visible light conditions.

A wireless night vision outdoor security camera has a highly sensitive CCD that not only captures visible light but is inherently sensitive to radiation in the near infrared spectrum. This allows the camera to produce high quality video images in conditions of total darkness, with absolutely no visible light. These cameras contain an collection of IR Light Emitting Diodes or IR LEDs that surround the camera lens. The LEDs emit IR light that is not visible to the human eye, but lights up the cameras target area or field of vision like a flood light or spot light. Usually, the more LEDs that surround the camera lens, the farther the range that the camera can produce IR video in total darkness. Since IR radiation is not in the visible light spectrum, IR video is monochromatic or black and white.

Another specialized feature of a wireless night vision outdoor security camera is that it does not require a coaxial cable to transmit its video signals to the systems processor. “Wired” security cameras must be individually cabled to the processing unit. A wireless camera utilizes the 2.8 or 5.8 MHz radio band to transmit its video data by using an on-board antenna. The information is transmitted to a corresponding receiver that is normally located in the same area as the processor. After the receiver obtains the video signal it transfers it to the processor where a digital video file is created that may be viewed on a monitor or stored for later viewing or archival proposes.

Wireless night vision outdoor security cameras are available in different transmission ranges. The range is known as Line-Of-Sight or LOS. This means that the maximum transmission range stated for the camera is under conditions where there is an unimpeded line of sight between the camera’s antenna and the receiver’s antenna. Objects between them reduce the range, depending on the object’s size and material. Wireless cameras have LOS range capabilities of several hundred feet.

Additional features available for wireless night vision outdoor security cameras include the ability to record audio and the pan, tilt, and/or zoom (PTZ) functions. PTZ functions allow the camera to move in several directions and the zoom feature functions like a variable telephoto lens. These features can be controlled automatically or they may be controlled manually by remote control.

A wireless night vision outdoor security camera can be used anywhere that outdoor day/night video security and surveillance monitoring is needed. These cameras are often used for perimeter monitoring for both businesses and residents. In addition that can be used to provide monitoring for parking lots, driveways, and outdoor structures.

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What is a LUX Rating?

Written By:
Wednesday, March 31st, 2010

Security cameras usually have a LUX rating. This LUX rating is the actual available light intensity at which the camera can produce a picture.

A LUX, abbreviated lx, is the International System of Units (SI) measure of the intensity of light. It can be thought of as the strength of light as determined by the human eye. A LUX is based on another unit of light measurement called a lumen, which is based on yet another unit called a candela. In the United States, the non-SI unit to measure light intensity is the footcandle. One foot candle is approximately equal to 10.8 LUX.

In order to put things in perspective, here some are some setting examples with their equivalent LUX rating:

• A quarter moon-lit night produces about .01 LUX
• A full moon on a clear night produces about 0.27 LUX
• A full moon on a clear night near the equator produces about 1 LUX
• An average family room produces about 50 LUX
• An overcast, dark day produces about 100 LUX
• Typical office lighting ranges from about 300 to 500 LUX
• Direct sunlight can range from about 30,000 to 130,000 LUX

The LUX rating of a security camera is based on several factors, three of which are the lens, sensor chip, and “F stop.” The lower the LUX rating of a security camera the less light is needed for the camera to produce a usable picture (video).

When considering sensor chip technology and LUX rating, there are basically two types of sensors used to produce an image, CMOS and CCD. CMOS sensors usually require a brighter intensity of light then CCD sensors and therefore cameras built with this sensor have higher LUX ratings. Generally, the greater the sensitivity of the sensor and therefore the less light needed to produce an image, the higher the cost of the camera.

In addition to sensitivity of the CCD or CMOS chip, the lens can affect the LUX rating as well. Light must pass through the lens and although a lens may appear as perfectly clear, it still absorbs some light as it passes through it. If the lens has any special filter technology, if it is unusually large, or if it is shaped in a unique way, these factors can all increase the LUX rating of the camera.

The camera has an opening or hole that the light passes through before activating the sensor. This is called the aperture or sometimes referred to as the “F-stop.” The lower the F-stop the closer to the camera the image will remain in focus. If the aperture is at a high F-stop, the objects farther away are in focus. Less light is needed for low F-stops to produce a clear image. More light is needed for a greater F-stop. Most cameras do not have a fixed F-stop per se; the iris controls the size of this opening and in most cases varies it as needed.

Most security cameras operate with a LUX rating of 1.0 or less. Some cameras have LUX ratings as low as .003 LUX. If a camera has a rating of 0.0 LUX it must be an infrared camera because a rating of 0.0 LUX means there is no available light and therefore an image can not be captured, unless it is through infrared imaging.

There are many factors that affect the LUX rating of a security camera. Talk with your professional security technician about your particular requirements. A professional security technician can help you choose the right LUX rated camera for your specific application.

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