Posts Tagged ‘ infrared’



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.

predator-shoulder-cannon

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.

NV1

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.

spec

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.

temp

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.

IR88

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.

snake

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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Common Issues With IR (Infrared) Dome Security Cameras

Written By:
Monday, September 26th, 2011

Common issues with IR Dome Cameras

This is a demonstration of issues you might find with IR Dome Cameras.

  1. If you noticed in this snapshot, you will see white spots around the image. This is caused when the lens is pointed straight up almost at 90 degrees. The lights are OFF and the IR’s are to close to the edge of the vandal dome housing. The light from the IR’s are bouncing back producing this issue.

Figure 1

Demonstration of camera been to closed to the edge of the camera dome cover

Figure 2

To fix this issue you must move the camera lens down to a point that the IR LEDs are not close to the edge of the dome cover. After you have the camera positioned away from the edge of the cover, the image should look like this:

Figure 3

  1. Another issue you might encounter after mounting this type of cameras are smudges and haze in the image. This issue is caused by having finger prints or dirt in the clear cover of the dome camera. This is an example of how it will look like when the dome is dirty:

Figure 4

I will be cleaning the surface of the camera with a microfiber cloth. It is recommended to use this type of cloth to clean the camera, because it will prevent scratches that might cause the IR’s to bounce back.

Right about to clean the camera

Camera image after cleaning the cover

There are many other issues that can cause IR reflection or bounce back. This includes:

  • The dome cover is not bolted in tight enough.

  • The rubber seal between the lens and the dome cover is not flush against the clear dome cover.

  • Another IR camera is in the field of view of this security camera and is causing white out areas.

  • There is a reflective surface above, below or in front of the security camera that is reflecting the IR light back into the camera.


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Dome Security Camera

Written By:
Friday, April 1st, 2011

The dome security camera is one of the most popular types of digital video security camera in use today.  Thanks to modern technological advances a lot of electronic power can be packaged inside a small 3.5 inch diameter dome camera.  Not only are they small and powerful, but the average dome security camera is light weight as well (in most cases weighing just under one pound), which makes it easy to mount just about anywhere.

Today, there are three standard types of digital video camera based on shape; the box type, bullet type, and dome security camera.  How, what, and where the camera is used usually dictates the type, although user preference is also a factor.

Dome cameras originated from their older analog ancestors.  These cameras were often big and bulky and required a great deal more depth than today’s dome security camera.  Often, the older cameras were actually box cameras placed behind a wall or ceiling with the body of the camera extending into the wall space ith just the lens extending through a pre-cut opening.   A glass dome was then fixed over the lens to make it more aesthetically pleasing.  Blackened glass or two-way mirror glass was often used to conceal the lens, so that potential shoplifters, intruders, etc. would not know in what direction the lens was aimed.

Current dome security cameras are nothing like what is described in the previous paragraph.  Considering that the main components of a digital video camera are the lens, the sensor chip, and the Integrated Circuit (IC) electronics the largest part of the camera is often the lens which on the average is about 3.6mm in diameter.

A digital video dome security camera is a compact, highly sophisticated electronic piece of equipment.   The sole purpose of the camera is to transfer light images into electronic images that can be seen on an electronic display device such as a monitor.

It does this by first using a lens to focus the field of view onto a tiny sensor chip.  These chips range from 1/3 inch to about 1/2 inch square.  One of two different sensor ships is used.  Although the chips go about the process differently, both yield the same result; transferring light into electronic impulses that can be measured (and therefore used to create an electronic image).

The sensor chips are either a Charged Coupled Device or CCD or a Complementary Metal Oxide Semiconductor or CMOS.  After the sensor chip converts the light image into an electronic impulse, the IC chips take over processing and digitizing the electronic information and passing it along to the Digital Video Recorder or DVR.

There are several types of dome security cameras based on how they function or where they are intended to be used.  Dome security cameras can be classified as indoor, outdoor, or indoor/outdoor types although most outdoor types today are the combination indoor/outdoor.  Indoor dome cameras are intended to be used inside, under protective cover from the weather and other elements.

Outdoor dome security cameras are protected by an outer shell or case that prevents water, snow, hail, or other damage to the camera itself.   These cameras are often rated according to the International Electrotechnical Commission’s (IEC’s) Ingress Protection or IP standard.   An IP rating of IP55 or higher is usually considered good.

Dome security cameras are usually flush mounted on a ceiling or wall, but may be mounted on special mounts that can range from peduncle type to horizontal extensions.  They require very little surface area for mounting, and can usually be mounted easily using from two to four screws.  The video transmission cable and the power supply cable usually attach from the underside of the mount or there are extensions exiting from under the mount such that the wires remain hidden and protected by the structure the camera is mounted on.

Dome security cameras may also work in InfraRed (IR) modes and the IR Light Emitting Diodes or LEDs are normally clustered right around the camera lens.   This provides directed IR illumination in the exact field of vision of the camera lens.

Security Camera King offers a wide selection of indoor and outdoor (as well as indoor/outdoor) dome security cameras.  Our cameras are of the highest quality and offer the best performance at the most economical price in the industry.

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