Posts Tagged ‘ InfraRed Light Emitting Diodes’



Infrared Camera System

Written By:
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!

 

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Weatherproof Bullet Security Camera

Written By:
Monday, May 2nd, 2011

There are very few bullet cameras these days that can’t be called weatherproof bullet security cameras.  In fact, all of the bullet cameras that we offer for sale at Security Camera King are weatherproof.  That is one of the benefits of owning a bullet security camera.

A weatherproof bullet security camera bridges the gap between the typical box camera and the conventional dome camera.  Box cameras are great cameras and have been around for a long time.  However, to maintain the box camera’s versatility it doesn’t come with all the necessary parts.

That is, for example, a box camera is usually sold as the body of the camera with the lens sold separately.  This is done to increase versatility, as you can always change lenses if you change the location or want a different field of view for the weatherproof bullet security camera.  However, this added versatility doesn’t come without added cost.

In addition, most box cameras were designed to be used indoors, under protective cover from the weather and the elements.  If you want to use a box camera outdoors, you will need to purchase an additional accessory, an outdoor camera housing.  While neither the lens nor the housing are terribly expensive, they are nonetheless, an expense that you need to consider when comparing cameras.

The dome camera is also an excellent camera.  Originally designed primarily for indoor use, the dome camera has come a long way in a relatively short period of time, technologically speaking.  Like the other models, dome cameras have their own advantages and disadvantages as well.  One such disadvantage is that due to their small size, dome cameras cannot support as many InfraRed Light Emitting Diodes (IR LEDs).  This ultimately means their range in conditions with little or no light will not be very long.

The weatherproof bullet security camera bridges the gap between the box and dome cameras because it features some of the items that are considered the very disadvantage of the other types of cameras.  For example, most bullet cameras come with a factory inserted lens.  Usually these are of the fixed type but there are many weatherproof bullet security cameras that come with varifocal lenses and motorized irises as well (See Security Camera King’s Product# OB-LX550IR150L922).

When shopping for a weatherproof bullet security camera, you probably will at some point, begin comparing each camera’s specification sheet. One term that we would like to clarify is the IP code or IP rating.  You’ll see this rating in the specifications as something like “IP65.”

IP stands for ingress protection and is a standard written and maintained by the International Electrotechnical Commission or IEC.  Its purpose is to provide specific descriptions of a camera enclosure’s ability to protect the camera inside.  An Ingress Protection rating has two digits (like the example in the previous paragraph).  The first digit represents the degree of protection from solids while the second digit indicates the degree of protection from liquids.

The first digit of the IP rating can range from 0 to 6.  A rating of 0 means there is absolutely no protection against contact and ingress or objects.  As this digit increases in value up to 6, each rating indicates protection from progressively smaller objects.  A rating of 6 for the first digit means there is absolutely no ingress of dust and there is complete protection against contact.

The second digit of the IP rating can range from 0 to 8.  Again, a rating of 0 means there is absolutely no protection against liquids.  As this digit increases in value up to 8, each rating indicates protection from progressively more intense contact with water.  A rating of 8 for the second digit means the camera is protected from continuous immersion in water deeper than 1 meter.  There for a reasonably good IP rating for a security camera would be IP55 or IP65.

Last but not least is the IR range.  Not all, but a good majority of the weatherproof bullet security cameras are also capable of IR video imagery.  This is accomplished by using IR LEDs to “light up” the field of vision.  This IR “light” is invisible to the human eye.

Generally, the more LED’s the greater the range and area of coverage under IR conditions.  Weatherproof bullet security cameras have lots of room for IR LEDs and can obtain fairly long ranges.  Before you buy the camera, make sure you check the range you will require so as to by the appropriate camera.

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SVS-54 Dual Power Wide Surveillance Camera

Written By:
Thursday, April 7th, 2011

The SVS-54 Dual Power Wide Surveillance Cameras are made by Veilux, a name known for extremely high quality products in the digital video security camera industry.  These cameras are the standard box camera type, with a dual power input capability.

The actual full name of the SVS-54 Dual Power Wide Surveillance Cameras is 540 TVL Dual Power Wide Dynamic Range Box Surveillance Cameras.  That’s a bit of a mouthful to swallow, but the cameras are every bit of what the label describes.

The SVS-54 Dual Power Wide Surveillance Cameras made by Veilux work off of 12 Volts Direct Current (VDC) or 24 Volts Alternating Current (VAC) hence the reference to “Dual Power.”  This is incredibly convenient in the event that you want to purchase this camera as an “add-on” camera to an already existing system, because the majority of digital video security cameras today operate on either 12 VDC or 24 VAC.  Since these cameras are dual power, they will operate equally well, no matter which of the two power systems you use.

These cameras are what are known as true day/night vision cameras as compared to an infrared illuminated camera that uses infrared Light Emitting Diodes (LEDs).  A True day/night camera such as the SVS-54 Dual Power Wide Surveillance Camera uses something called an IR Cut Filter to provide the day/night feature, instead of using illuminating infrared LEDs.  Cameras using IR Cut Filters are generally more advanced than IR LED types producing a much cleaner brighter, detailed image whether it is operating in day mode or in night mode.

The IR Cut Filter works by sitting in place in front of the CCD sensor during the day and blocks out stray infrared light from entering the camera.  This stray infrared light often causes distortion of the image and incorrectly displayed color characteristics.   In night mode, the filter is literally moved out of the way of the sensor (i.e. mechanically repositioned).  This allows all light, including visible and infrared to strike the camera’s CCD sensor.   Since the sensor is inherently sensitive to IR light, this allows the camera to “see” more in less light.

The IR cut filter and special sensor combination allow the SVS-54 Dual Power Wide Surveillance Camera to produce high quality, detailed video in bright visible light conditions all the way down to the lowest Lux (brightness) conditions.  Combine this with technology that produces up to 120 dB or dynamic range and that’s why this camera earns the title “Wide Dynamic Range” or WDR.

This camera also produces a high definition, highly detailed video image.  In fact the video image produced by the SVS-54 Dual Power Wide Surveillance Camera is 540 horizontal television lines (TVL).  This a fairly high-detailed resolution, especially for a camera that can operate without infrared illumination at incredibly lo Lux ratings.

Other features of the SVS-54 Dual Power Wide Surveillance Camera include On Screen Display, Motion Detection, and back light compensation.  These extra features contribute even more to the high versatility of this camera.

Which leads us to the question, “Where would you use an SVS-54 Dual Power Wide Surveillance Camera?”  The answer is just about anywhere.  Although this camera is an indoor camera, it can easily be placed in an outdoor rated enclosure and used outdoors as well.  The Wide Dynamic Range and extreme low light sensitivity makes this camera an excellent choice for used indoors or outdoors.

Mentioned earlier, the dual power function is another benefit that adds to its versatility.  Besides the fact that there are no worries about needing to convert this camera’s  power supply to meet DC or AC, the fact that it can operate on AC makes it an excellent choice for special long-range applications.  Direct Current has a tendency to weaken, or experience voltage drops, the longer the distance it is sent, primarily due to inherent resistance of the wire that carries the current.  (Unfortunately, this cannot be avoided).

However, AC has the opposing characteristic of being able to be shipped long distances without tremendous power loss.  Therefore, this camera is excellent for applications where the camera power supply must be run a long distance (several hundred feet for example).

At the time of this writing, Veilux is temporarily out of stock of the SVS-54 Dual Power Wide Surveillance Camera so it is on SCK’s discontinued list.  For a similar camera but with a high resolution, check out SCKs Product# SVS-60CDNRD.

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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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