Posts Tagged ‘ ir light emitting diodes’



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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OD-LX520IR50 Vandal Resistant Dome Camera

Written By:
Friday, March 25th, 2011

Security Camera King’s (SCK’s) OD-LX520IR50 Vandal Resistant Dome Camera is the featured camera for all of SCKs Ultimate series DVR complete package systems.  Although this camera sells individually for only $74.95, it’s a very high quality high definition camera that produces detailed video and comes packed with many useful features.

The OD-LX520IR50 Vandal Resistant Dome Camera may be used indoors or outdoors and is rated at IP66.  The IP rating is the International Electrotechnical Commissions (EIC) standard for Ingress Protection; in other words it is a rating that grades the amount of protection that is afforded to the camera from weather and other elements.

A rating of IP66 means that the camera is dust tight and is completely protected against contact with dust.  In addition, the camera can withstand powerful water jets projected from a 12.5 mm nozzle against the enclosure without any harmful effects to the camera.

The OD-LX520IR50 is a vandal proof camera which means it has been designed in such a manner as to prevent as much mischievous damage to it as possible.  There are no exposed screws, the case is rugged and durable, and even the video transmission and power supply cabled can be run from behind the camera to prevent exterior exposure.

The camera is also a night vision InfraRed camera.  This camera can create crisp, clear detailed video images in total darkness and has a total darkness IR range of approximately 50 feet.  This is supported by the 23 separate IR Light Emitting Diodes (LEDs) that surround the camera lens and flood the camera’s field of vision with IR illumination.  Although this IR illumination produces a bright, nice contrast video image, it cannot be seen by the human eye.

The OD-LX520IR50 also has back light compensation to automatically adjust for subjects that could otherwise be distorted to back lighting.  It also comes with auto white balance for proper contrast and brightness control.  The included lens is a small 3.6 mm/F2.0 lens.

For the technically inclined, we’ll provide the following additional information.

The OD-LX520IR50 utilizes a SONY 1/3″ CCD with a horizontal resolution of 520 TVL (television lines).  It’s signal to noise ratio is more than 48 decibels and its clock frequency is NTSC 28.636 MHz and a 2 to 1 interlaced scanning system.

The minimum operating illumination is 0 Lux because the camera is an IR camera that can operate in total darkness.  The 23 IR LEDs that surround the lens can provide a working range up to 50 feet, but greater lengths can be obtained using additional IR illuminators.  The IR mode begins working when the ambient light dims to less than 10 Lux which is detected and then IR is initiated by a CdS (Cadmium Sulfide) cell (i.e. photocell).

The camera has an internal, negative synchronous system with a Gamma rating of 0.45 and an auto electronic shutter speed range of from 1/60 to 1/100,000 of a second.  It has a video output of 1 volt peak-to-peak at 75 ohms with auto gain control.  The camera operates on 12 Volts DC with a draw of 300 mA (this includes the IR LEDs).

The camera is small, compact and light weight.  The camera dimensions are 3.7 x 2.7 inches at weighs just under one pound (15.9 ounces)

The OD-LX520IR50 is durable an can operate within a fairly large temperature range.  The camera has been field tested for storage only at temperatures ranging from -22 degrees F through +140 degrees F and has a significant operating range of from 14 degrees F through 113 degrees F.

For more information and customer reviews check out the OD-LX520IR50 Webpage at http://www.securitycameraking.com/520tvl-indoor-outdoor-vandal-resistant-57813-prd1.html or contact on of our security experts via on-line “Live Chat” or by telephone at 866-573-8878 Monday through Friday from 9AM to 6 PM EST.

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