Posts Tagged ‘ night vision’



Different Security Camera “Night Vision” Options

Written By:
Wednesday, September 17th, 2014

Did you ever wish you could see at night? Well believe it or not, it’s more common than you might think.

Several security cameras have the ability to see at night or even in complete darkness with the assistance of Infrared. Actually there are a few different types of infrared CCTV cameras. Two of the most popular options are FLIR Cameras, that stands for “Forward Looking Infrared Radiometer” and the more common standard infrared technology used in the majority of today’s consumer based security cameras.

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Thermal Imaging & Night Vision
Forward Looking Infrared cameras, sometimes known as thermal cameras, use an array of sensors that can pick up infrared (IR) emissions or detect heat. This is because heat emits IR light. The hotter something is, the more IR it emits. The FLIR camera displays the different levels of heat that it detects as different colors or shades of color.

Anyone who has seen the movie “Predator” might associate FLIR images with the way the predator sees his enemies or prey via his high tech helmet.

FLIR cameras are used for a variety of applications and industries including, but not limited to, law enforcement, military, building & home Inspections, leak detection, commercial & personal security, and hunting & survival.

When it comes to seeing in the dark, FLIR Imaging has many benefits over traditional night vision. Night Vision devices simply magnify the available natural or manmade light in a specific area to brighten an image and help you see in very low light. In many situations there’s still not enough light for the human to see contrast between objects. Everything gives off heat and because thermal cameras see heat instead of light, you can see a lot more contrast between objects.

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Environmental conditions such as rain, fog or smoke can also displace natural light making it hard to see or completely mask your target when using traditional night vision. This is not the case with thermal imaging.

Here is a great video “Night Vision versus Thermal Imaging” that shows visual examples of these differences.

The Spectrum
As I mentioned before FLIR and the more common types of CCTV cameras use IR or Infrared to see at night.

Take a look at the chart below. Notice the area marked “”Visible Light”, this is the part of the spectrum that is visible to the human eye.

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Just to the left of the visible Violet light is Ultra-Violet and to the right of visible red is Infra-RED. Like ultraviolet, infrared is light that is not visible to the human eye. CCTV cameras have a special chip inside that acts as the camera’s eye, but it can see infrared light. That’s why even though we can’t see in the dark, security cameras can.
There are actually different intensities of infrared: near, mid and far infrared. Near-Infrared is just outside the spectrum of red that humans can see. Most commercial security cameras see near-infrared, and like the human eye they can see the light that reflects off of objects. Thermal imaging uses the far-infrared part of the spectrum and can actually see the IR that is produced by heat, not the reflective light. The hotter the object is the more IR it emits.

A Discovery
Infrared light also known as infrared radiation was discovered in the 1800’s by William Herschel. He wanted to measure the temperature for each color of light in the spectrum.

He hung a prism in a window and projected the light spectrum onto a desk. He used a thermometer to measure the temperature of each color. He tested Violet, Blue, Green, Yellow, Orange and Red light. He realized that the temperature increased from violet to red. Then he decided to measure the temperature just outside of the red area where no light was visible. Surprisingly this area was even hotter than the areas were colors could be seen. It proved that there were types of light not visible by the human eye.

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A Question
Question: How do we know that Infra-red light is actually RED? In the light spectrum yellow light has green next to it, so how do we know the color next to red is red? Could it be a color we don’t even have a name for?

Infrared CCTV Camera LED’s
Most security cameras on the market these days use infrared LED’s to produce infrared light. The amount of light produced as well as the distance the camera can see at night depends on the intensity, size, and number of LED’s used for each individual camera.

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The security cameras also have a built-in photo cell that detects light. When the sounding light levels get too low, the infrared IR’s will turn on automatically.

On some cameras you can actually see the LED’s emitting a slight red glow when the IR’s turn on. Many CCTV installers will test whether or not a camera is getting power by cupping the front of the lens with their hands. By doing this it blocks the light and turns on the IR’s. If you peek into your hands while the IR’s are on and can see the red glow, that lets you know that the camera is getting sufficient power.

A Little Help
Most CCTV cameras have a maximum IR distance. This is basically the distance that the camera can see at night. The more powerful the IRs are the greater the distance the camera can see.

The infrared light source does not have to come from the camera itself. Many security cameras will detect any available infrared light in the surrounding area.

Whitelight

If you have a camera that does not have Infrared IR’s built-in or IR’s that do not have enough power to see the distance you desire, you can use an IR Illuminator. IR Illuminators are basically like big IR flood lights that can be mounted next to the camera, or in any location within the cameras field of view that you want illuminated. Similar to built-in camera IR’s they have a photo cell and will turn the IR’s on and off automatically.

Who’s There?
Some cameras use a more simple approach to be able to see at night.They use a built motion detector. When the camera detects motion a “White Light” or “LED” turns on and illuminates the surrounding area, similar to turning on a very bright flashlight.

Some Interesting Facts
Fact: Some Snakes have special organs that allow them to see Infrared. This enables them to strike their pray precisely regardless of the light conditions.

Pop Culture: In 2002 the video game “Tom Clancy’s Splinter Cell” was released. It featured Sam Fisher, a special agent for the NSA as the main character. It was one of the first video games to encourage the player stay in the shadows, sneak up on their enemies and take them out silently, instead of running out in the open with guns blazing. Ironically 2 of his most powerful weapons were night vision & thermal vision.

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In Conclusion
The next time you find yourself stumbling around in the dark, just remember that how many different types of “Night Vision” there are. Humans have come up with a verity of methods to achieve artificial night vision. Some animals are equipped with biological night vision and it is prevalent in areas such as the military, home security and even in video games.

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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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