Archive for 2011



IP Security Camera

Written By:
Thursday, December 29th, 2011

Nothing has more “global” access in the digital video security camera industry than an IP (Internet Protocol) security camera.  These cameras use the Internet as the means for their transmissions so anyone with a broadband Internet connection and a computer can access these cameras. The outreach available for use and/or monitoring has been extended even further with the increased technology in cell phones, namely 3G and 4G broadband Internet access.  In the following article we’ll take a look at some Internet security camera systems and how they work.

How a Non-IP Camera System Works

How a Non-IP Camera System WorksFirst, let’s make sure we understand how a “non-Internet” security camera system works.   In this type of system, digital video security and surveillance cameras capture video footage and send the video data to the Digital Video Recorder or DVR via a closed circuit made up cable, usually RG-59 coaxial cable or CAT5 Ethernet cable.  There are wireless systems also.

The wireless system consists of an antenna and transmitter built into the camera.  The receiver is usually located near the DVR and is attached to it by the cable mentioned above.  This is still considered a closed circuit television system because even though the camera is transmitting its signal wirelessly in is done on a private, specified frequency.

The DVR stores the video on a hard disk drive (HDD) just like the HDD found in a personal computer.  In addition the DVR may also display the video in real-time (live) on one to several monitors for surveillance purposes.  Some IP security cameras also offer the capability of storing video footage locally on the camera.  A miniature DVR of sorts is built into the camer so that footage can be saved locally on portable memory/storage media such as an SD card.

The digital video camera is responsible for capturing a light image and transforming it into an electronic image.  It does this by using a lens to focus what can be a large field of vision onto a small electronic sensor which usually ranges in size from only 1/4 inch to 1/2 inch square.

One of two different sensor chips is used for this purpose.  They are the Charged Coupled Device or CCD and the Complementary Metal Oxide Semiconductor or CMOS. When light strikes these sensors they emit electrical charges which can be measured and used to create a video image.  The data that is created by these chips is actually analog in form until it passes through an analog-to-digital converter chip.  Another highly specialized electronic chip called a Digital Signal Processor or DSP insures the integrity of the data and may make any corrections that are necessary.

At this point, the camera passes the digital data along to the Digital Video Recorder or DVR whose job is to record the data and store it as mentioned above.  It does this by compressing the file into a fraction of its original size but still managing to maintain a high quality.  It does this by using a COmpression/DECompression or CODEC utility.

How an IP Camera System Works

IP Security CameraAn Internet security camera system is very similar to the above system, however once the data becomes digital, it opens up a whole new world of possibilities, especially including the use of the Internet.  There are basically two types of Internet security camera systems.  One system consists of cameras that are Internet compatible also called Internet Protocol ready or IP ready.  The other system consists of a DVR that has its own Web server technology and is called IP ready as well.

IP ready cameras contain their own web server technology so that they maybe connected to the Internet.  Instead of sending their digital data directly to a DVR, they send their data via the Internet to anywhere there is a client that wants to access the information.  Generally these cameras use two CODECs at once.  Many of the cameras pass the information on to the DVR using the MJPEG CODEC while streaming the information via the Internet for live viewing using the latest CODEC, H.264.

These cameras may direct their video via the Internet to a specific type of DVR that is designed for this purpose which is called a Network Video Recorder or NVR.  One of the advantages of this system is that multiple cameras in multiple locations can be recorded by the NVR.  These locations can be widespread, such as two or more commercial facilities that are located in two different cities.  An Internet security camera system of this type can lend itself to all sorts of networking possibilities.

Another type of Internet security camera system exists where the DVR is the IP ready device and it takes care of all Internet related inquiries.  In this system, the cameras are not IP ready and they send all of their digital data to the DVR.  The DVR then contains its own Web server technology and allows a client access to the system through the DVR.  All of Security Camera King’s featured DVRs have these feature built in to the DVR.

This internet security camera system records the video locally on the DVRs HDD, but it allows a user to control the DVR and in many instances, even the cameras (for example, PTZ movements) remotely.  As a matter of fact, these systems can ever be monitored and controlled using a smartphone and 3G or 4G Internet technology.

Additionally, the IP Camera/DVR can be set up to send alerts if the camera includes (and most do) motion detection.  Specifically, the user can have emails sent to then upon a variety of different triggers.

Wireless IP Security Cameras

In addition to using the Internet as the vehicle for delivering the digital data to its final destination, the wireless IP security camera may have the capable of connecting to the Internet wirelessly.  Although non-IP wireless cameras can be wireless as well, their wireless architecture is limited to a couple of different methods while the IP security system has the same wireless architecture but may have a few extra methods that only the IP camera can utilize.

Most wireless non-IP security cameras use a couple of different specific methods for transmitting their data.  Probably one of the most often used methods is the 2.4 or 5.8 GHz transmission method.  Some also use the 900 MHz technology, although as technology increases, there seems to be less of a tendency for using the 9000 MHz technology.

The 2.4 or 5.8 GHz technology boosts ranges possible of up to 5 miles Line Of Sight or LOS.   LOS means that the manufactures specification for range in length is dependent on objects that could impede the signal.  LOS means that the range is directly from camera transmitter to receiver, although this is an ideal situation and seldom does it ever really exist.  As a matter of fact if something does impede the LOS it usually reduces the range but does not entirely disable the wireless signal.  In fact, it usually just decreases the length of the range based on the material involved such as trees, walls, buildings, glass, etc.

Wireless IP security cameras on the other hand use a different mechanism for wireless transmission; normally wireless Internet known as WiFi.  WiFi is basically a brand name for products using the IEEE 802.11 standards.  Typically, wireless IP security cameras using WiFi have about a 65 foot maximum “hot-spot” to connect to their wireless router or modem that receives the WiFi signal.

Benefits and Differences of IP security Cameras

First and foremost IP network security cameras are capable of producing video at an extremely higher resolution than standard non-IP systems.  The highest resolution non-IP camera can record with a maximum regulation known as “D1″ which is 720 x 480 pixels.  A 3 megapixel IP security camera can record at a resolution equal to 2048 x 1536 pixels; this is about 9 times greater detail than D1.

Equally amazing is another benefit involving networking.  Non-IP cameras send their signals to a DVR.  IP cameras send their signals to an NVR or Network Video Recorder.  So what’s the difference?  Non-IP cameras are normally located in one general geographical area, i.e. the digital video cameras in a department store connected to a DVR in the stores office.

As mentioned above, IP cameras use NVRs instead.  Most IP cameras can be located anywhere you want to put them (geographically speaking) and although they are in totally different locations they can all be routed to the NVR via the Internet.  In other words, you may own three small convenient stores in a city.  If each convenient store has IP cameras, their video signals can be sent to somewhere not even connected with the geographical area of the cameras such as a home, home office, or office location.

IP cameras are available in a myriad of types sizes and functions.  Security Camera King currently offers 3 different cameras:  1. 3 Megapixel IP Network Box Security Camera Product # IPBC-EL3MP; 2. 3 Megapixel IR Vandal Dome IP Security Camera Product # IPVD-EL#MPIR; and, 3. 18 x 1.3 Megapixel IP Network PTZ Security Camera Product # IPPTZ-EL13mpl18x.

 

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Nanny Cams

Written By:
Wednesday, December 28th, 2011

Nanny cams are hidden cameras that have been installed in common, every day household items.  The camera is used (secretly) to monitor and record the daily activities of home caregivers; hence the name “Nanny Cam.”

A Nanny cam can be used remotely, where it’s video is transmitted by radio waves to a receiver hooked up to other devices (Digital Video Recorders or DVRs, sent over the internet,)  or you can use a “hardwire” run which, unless your careful, will more than likely stick out and be easily seen.

Are Hidden Nanny Cams Legal?

It is generally legal to videotape nannies without their permission; however, using cameras with audio can impose legal ramifications since it may fall under “eavesdropping” or “wiretapping” laws governing use of a device with an audio component to tape a sitter without consent.  These laws vary from state to state. Check with your local laws to confirm.

We all have expectations of privacy in private places. But should we expect privacy in the home of another? The answer is “NO.”
Parents and other proponents of nanny-cams argue that the installation of a hidden camera in their own home is not an invasion of privacy.

The court has agreed. In State v. Diaz, 706 A.2d 264 (1998), the leading case on this topic, the court ruled that a videotape made by a hidden camera in the residence of the parents of the child was admissible as evidence in the lawsuit against the nanny for assault and child endangerment. The court decided that since there was an absence of state action, the Constitution did not protect the nanny’s privacy in someone else’s house.

The court also held that a videotape without sound did not violate the Wiretapping and Electronic Surveillance Control Act, but furthermore, that sound was admissible because the parents had consented to their child being taped.

States vary on this particular issue, but most agree that a videotaping your nanny without her knowledge is perfectly legal so long as there is no sound. Audiotaping without the nanny’s consent is an issue upon which the states are split.

There are a variety of reasons people choose a Multi Camera System. Many parents who are using a nanny service for the first time want to make sure that their choice of a nanny is good. Many times you will find out about a nanny’s behavior in the first month or two. The fact that one’s child has been entrusted to someone you hardly know can be a big leap of faith. Parents may be concerned about a sitter’s everyday behavior such as smoking or cursing, or they may have greater concerns of whether the caregiver is paying enough attention to the child, or is physically or emotionally abusing the child.

“I want to know when I leave and close that door what’s going on behind it. I want to know my child is safe and being nurtured, played with, sang to and loved,” says Maria. “I think the ethics go right out the window when it comes to protecting our children. Caregivers are paid to keep your kids safe and happy, not to get mad at your kids, yell at them and hit them or put them in a swing all day and neglect them.

Most nanny cams are set up so they do not record audio but do record video.  There’s a very good reason for this.

According to the US Code Title 18, Chapter 119, Section 2512 prohibits the interception of oral communication by “surreptitious manner,” such as a hidden camera, and so most nanny cams are not available with audio recording. Though some on the market may be available with the ability to record audio, these cameras should not be used due to the illegality of the recordings they produce. Nanny Cams are legal in all 50 states,but it is illegal in 13 states to record audio without express, or written consent of the nanny being recorded. This falls under the federal governments wire tapping laws.

However, there’s also a very good solution for all of this and that is purchase whatever kind of camera you feel most comfortable with and when installing it, simply do not connect the audio.

Why Use a Nanny Cam?

“2008 – A couple said they did everything possible to make sure the child was in safe hands when they discovered abuse by the nanny by using a hidden nanny camera.”

“Stephanie M. the subject of a widely publicized nanny cam video recorded by her employer faces two misdemeanor counts of child abuse in Cary, North Carolina.”

“A Florida nanny is behind bars for allegedly abusing an 11 month old child.  The abuse case was captured on a hidden nanny cam.  Investigator Adrian K speaks about some warning signs of abuse cases.”

“Nanny cam captures abuse on tape; A Florida babysitter is jailed after video shows her slapping an infant.”

Unfortunately, there are many more incidents like those listed above.  These real examples do indicate a very strong case for the use of a nanny cam.  The use of a nanny cam is not limited to monitoring the care of an infant.  The use of a nanny cam can not only protect children but may be able to support a nanny or baby sitter when children make untruthful claims of abuse to their parents.  The bottom dollar is anytime it’s necessary to keep track of who’s watching who the nanny camera setup is an excellent choice.  And the camera doesn’t lie.

What Exactly is a Nanny Cam?

A nanny cam is a digital video camera that may be hidden, disguised, or even fully exposed  and is used to monitor the day to day activities of your nanny and child(ren).  There may be one or more cameras based on the type of coverage you desire.  For example some parents feel comfortable placing just one camera in the child’s room, nursery, or play area.  Others prefer to have coverage in just about every room in the house; the choice is yours and with today’s high tech cameras and Digital Video Recorders (DVRs) it is not only possible but economically feasible as well so the average family can easily afford a digital video surveillance system.

How Do Nanny Cams (or Cameras) Work?

The following is a brief description of the technical aspect of typical digital video camera:

Digital video surveillance and security cameras have gone through many changes over the past few years and are ever changing with the increases in technology.  Older systems used strictly analog cameras with analog video recorders.  A bit of irony exists today because “digital” video cameras today still produce an analog image but it is converted to a digital image before it leaves the camera.

Nanny cams basically consist of three major components: 1. The lens; 2. The sensor chip; and, the Integrated Circuitry (IC) or IC chip.

Let’s begin our description with the lens.  The lens’ primary function is to capture light reflected from objects in its field of view and focus them onto the tiny sensor chip that converts the light energy into electrical energy.  Lenses may be specified as fixed or varifocal.  A fixed lens cannot move and the angle of vision or field of vision is fixed at one particular size.   A varifocal lens can move in and out changing its focal length and thereby changing the angle of the field of vision from wide to tight.

The aperture is also considered part of the lens.  The aperture is diaphragm type hole that the light must pass through as well.  This is for controlling the amount of light focusing on the sensor chip.  Generally, a very bright shot requires a small aperture so the shot is not completely washed out with light.  Under conditions when there is not enough light, the aperture opens fully to let as much light in as possible.

Once the light passes through the lens and aperture it strikes a photoreceptive sensor.   There are actually two different sensors that are available for use when manufacturing a nanny cam.  Each works in a different way yet they bear the exact same results; transferring light energy into electrical energy that can be measured.

One of the sensors is called a Charged Coupled Device or CCD and the other is called a Complementary Metal Oxide Semiconductor or CMOS.  Each of these sensors come in different sizes but for a typical high-quality nanny cam they are usually 1/4 or 1/3 inch square.  As the focused light strikes the surface of the CCD or the CMOS the sensor transfers the light energy into electrical energy which can be measured and manipulated to create a digital video image that can be viewed on a monitor.

The camera is basically the same as a camera that creates photographic images.  The difference is the nanny cam takes several photographic images, usually from 7 to 30 per second, also called frames per second or fps.  At 30 fps the human brain is fooled into thinking that it is seeing fluid motion.  This is the same concept that has been used for years in the motion picture industry.

On inherent quality of both the CCD and the CMOS is that they are also sensitive to Infrared Radiation, specifically IR in the near zone of the IR spectrum.  This means that by using IR Light Emitting Diodes as spot lights, these cameras can “see” in total darkness.  The human eye however, cannot see the light created by the IR LEDs which makes these cameras excellent for monitoring dark rooms.

The DVR

The DVR for a nanny cam can be a typical DVR that is used with a complete system or the camera may contain a “built in” DVR so that the camera and DVR is all one self-contained unit such as the pen camera.  The ink pen camera is a working ink pen, a camera, and a DVR all in one unit (this is a good example of how technology is used in the video surveillance industry).  When the user is ready to review the video footage they plug the pen into a USB port on their computer and sit back and watch the footage.

Other camera/DVR single units may use SD cards, Mini cards, USB Flash drives, and other portable memory media as their DVRs.

What Camera Do I Use?

Security Camera King has many hidden or disguised cameras that make excellent nanny cams. Below is a partial list of just some of the cameras or camera/DVR combinations available:

  • Button cameras – this cameras are actual buttons an come with extra buttons that are the same type as the one used on the camera to complete its total disguise;
  • Phillips head screw camera – That’s right a camera the size of an average screw head!
  • Desktop speaker camera – These look and work like typical computer desktop speakers but with one difference, one speaker has a camera inside;
  • Wall clock and alarm clock cameras;
  • A wall heater/air conditioning thermostat–although the thermostat does not actually work the hidden camera inside does;
  • Circular vanity mirror with touch activation;
  • Carbon monoxide or smoke alarms – these units usually don’t work as alarms but the do a great job of hiding the camera; and
  • Telephones and even a Tissue Box with embedded cameras.

Of course this is not a complete list of available cameras from Security Camera King but it should give you a good idea of what is available.

This still doesn’t answer the question as to what camera to use, but at least you have a better idea of what is available.  First, you need to determine how extensive your nanny cam coverage will be so you know how many cameras you will need to do the job.  As mentioned earlier, it can be a s few as one camera or as many as several.

The next step is to determine if they will be overt or covert cameras.  If your monitoring is overt standard box, bullet, or dome cameras would be sufficient.  On the other hand, if your coverage is going to be covert, you need to consider what type of disguised or hidden camera will satisfy each location.

If you determine that you only need one camera, a standalone hidden camera/DVR unit may be the answer.  However, if you desire entire home coverage with say, 8 cameras, it may be best to install a digital video security and surveillance system with a full-service 8 camera DVR.

And finally a word of caution.  Each state has different laws governing the use of cameras and especially audio recorders without the subject’s knowledge.  Make sure you confirm your state’s laws before attempting to record anyone covertly.  This doesn’t mean that you can’t record improper or criminal activity but planned, deliberate, covert recording may require special concessions on the part of the person recording.

As you can see, with a little guidance and pre-planning setting up your own nanny cam really isn’t difficult to do.  If you do encounter problems contact Security Camera King’s security experts and they’ll be glad to answer any questions you may have and get you up and running fast.

If you neeed more information on nanny cams contact one of Security Camera Kings security experts and they will answer any additional questions you may have.

 

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High Resolution CCD Camera

Written By:
Thursday, December 22nd, 2011

Security camera lines of resolution are one of the factors that determine the size, fineness, or quality of a high resolution CCD camera. Most often, this figure is referenced in TVL which stands for Television Lines and is usually used to reference analog type video quality. Digital resolution is usually referenced in terms of pixels. Let’s take a look at both and see how the lines of resolution relate to high resolution CCD camera picture quality.

High Resolution CCD Camera

First, there are different formats of video that are used in different geographical areas. NTSC (National Television System Committee) format is used in North and South America, Japan, and Taiwan and many other areas. PAL (Phase Alternating Line) format is used primarily in Africa, Asia, New Zealand, Australia, and the majority of Europe. SECAM (in French, SEquentiel Couleur A Mémoire, meaning Sequential Color with Memory) format occurs in parts of Africa and in the Russian Federation. Without getting too technical, we will just focus on the NTSC format.

A standard NTSC analog video is composed of 480 interlaced horizontal lines. The number of horizontal lines displayed must be counted vertically, one above the other and so on. Security camera resolution in TVL is a specification that refers to the horizontal resolution which is the number of vertical lines visible in a certain area of a monochrome picture. The number of vertical lines is counted horizontally, one next to the other and so on. Although TVL is not exactly equal to the number of scan lines, it is directly affected by the number of scan lines.

Most security camera video is displayed in a 3X4 aspect ratio. This means a display in the shape of a rectangle, 3 units wide by 4 units high. Since horizontal resolution is equal to the number of vertical units (lines), it is actually the measure of detail that can be seen in 75% or ¾ of the pictures width. TVL then is the number of vertical lines that take up the space of 3 units. In other words, on a picture that is 3 inches wide by 4 inches high with a TVL of 420, there are 420 vertical lines in the 3 inch width.

High resolution CCD cameras come in a variety of resolution specifications based on manufacturer, uses, and price, but for comparison purposes, a typical “standard” CCTV camera has a resolution of around 380 TVL while a typical “high-resolution” CCTV camera has a resolution of 540 TVL or higher. At the present time it seems that the highest resolution CCD camera can attain a resolution of 700 TVL.

The TVL resolution number is an indication of the actual inherent quality of a security camera or monitor and should not be confused with the actual horizontal scanning lines of broadcast television systems.

These lines of resolution apply to analog type video. Digital video resolution is somewhat different. Digital video is still displayed in a 3X4 aspect ratio. However, the resolution is measured in pixels (small points, dots, or squares). Like the analog cameras, digital cameras have a sensor, called a CCD or Charged Coupled Device that captures the picture in digital format. The digital picture resolution is referred to in terms of pixels such as 352X240 pixels. The three most common digital security camera resolutions include 704 x 480, 352 x 480, and 352 x 240 pixels.

600TVL Color Day Night Vandal Proof Dome Surveillance Camera

Do not confuse the display resolution of the camera with the number of pixels of the CCD. The CCD sensor consists of millions of light sensing cells. The number of pixels produced by the sensor is called the pixel count. For example, a camera that can produce an image size of 640X480 would contain 307,200 pixels. A CCD capable of producing an image size of 3872×2592 would need to produce 10,036,224 pixels or 10 megapixels. This CCD rating in megapixels is often erroneously interpreted as the camera resolution. It more correctly indicates the maximum potential resolution the camera could produce when used in conjuntion with other high-quality equipment such as monitors, processors, etc.

To put everything in perspective, the following provides a summary comparison of both analog TVL and digital resolution with picture quality increasing as the number of the items increases:

1. 352X240 pixels (digital)

2. 330 TVL (analog)

3. 380 TVL (analog)

4. 480 TVL (analog)

5. 704X240 pixels (digital) and 704X480 pixels (digital)

6. 570 TVL (analog)

If you have any questions concerning high resolution CCD cameras please contact one of our security experts via on-line “Live Chat” or by telephone at 1-866-573-8878.

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Pan Tilt Zoom Internet Cameras

Written By:
Tuesday, December 20th, 2011

Pan Tilt Zoom Internet CamerasPTZ or Pan Tilt Zoom Internet cameras have the freedom of mobility to move about a horizontal and vertical axis thereby increasing the field of view for the camera.  In fact in some situations one Pan Tilt Zoom Internet camera may be able to perform the work of two or more stationary cameras.  In addition, the zoom function allows combinations of lenses to create telephoto enlargements for better clarity of objects that may be too far away from a normal camera lens.  These cameras also have the benefit of using the Internet too monitor and control the cameras.

 

Pan Tilt Zoom Internet cameras are excellent for use in retail stores where tracking and zooming in on a potential shoplifter may be needed.  Depending on the size of the store, the location of the camera, and the type of camera, it may be able to follow the shoplifter the entire route that’s made in the store.  Considering the high rate of retail theft that’s been reported lately especially in the major metropolitan areas, Pan Tilt Zoom Internet cameras are ideal for this purpose.

 

Pan Tilt Zoom Internet cameras are not limited to use in parking lots and retail stores; they have many other useful applications as well.  Let’s take a closer look at a Pan Tilt Zoom Internet camera.

 

Pan-tilt-zoom cameras are usually, but not always dome-type cameras.  These cameras are usually mounted on the ceiling with the orientation of the dome (and thus the camera lens) downward.  They may also be mounted on brackets on a horizontal surface (such as a wall or pole) with the brackets extending away from the horizontal surface just enough to provide clearance for hanging the dome in a downward position.

 

Pan Tilt Zoom Internet cameras may be indoor or outdoor models.  Outdoor models are basically the same as indoor models but are enclosed in a protective case or cover.  The outdoor cameras are normally rated according to the International Electrical code standard for the protection they offer from weather and other environmental elements.  This rating, called an Ingress Protection code or IP rating consists of two numbers that represent corresponding protection standards.  For an outdoor PTZ camera, look for a rating of IP66 or IP67.  Both ratings indicate the cameras are dust tight but the IP66 also indicates that the camera can withstand powerful jets of water from any direction while the IP67 also indicates that it could be submerged in up to 1 meter of water without damage.

 

Some PTZ cameras are set manually, but the majority of Pan Tilt Zoom Internet cameras marketed today are remotely controlled.  This is normally done by a keyboard or joystick control connected to the processing unit/digital video recorder or DVR.  If the camera is connected to a personal computer or the Internet, it may use the computer’s keyboard and/or mouse, or may provide software that has graphics that are used to control the cameras.

 

Pan Tilt Zoom Internet cameras may also come with software that can be used to preprogram the movement of the camera.  Programmable preset points will move the camera to that position and hold it there for a predetermined amount of time (often referred to as a “dwell time”).  After moving to each preset point and holding, the camera returns to the first preset point and repeats the cycle over again.  Different cameras have a different total number of preset points available. When looking for a PTZ camera with this option, check the specifications to make sure the camera can be programmed for the number of presets you will need.

 

Most Pan Tilt Zoom Internet cameras also have the ability to detect motion.  This is not so much a function of the camera as it is the programming or software that is controlling it.  However, once these cameras detect a moving object they have the ability to “lock on” to the object and follow it throughout the total range of view for the camera.  If cameras include the zoom option, they can even zoom in on the object while following it.  These cameras are usually referred to as “Auto-Tracking PTZ Cameras.”

 

PTZ cameras are incredibly versatile, easy to install, and reasonably priced making them an excellent choice for many business and residential applications.  Contact one of our security experts today for more information either via Live Chat or by telephone at 866-573-8878 Monday through Friday from 9AM until 6PM EST.

 

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Micro DVRs

Written By:
Thursday, December 15th, 2011

Micro DVRsThere are certain applications for surveillance and security where a “standard” Digital Video Recorder or DVR is just too large.  For these applications the best choice is a micro DVR.  Micro DVRs can be so small as to fit inside the casing of an ink pen.  Let’s take a look at a digital video system that uses standard size DVRs first, and then take a look at micro DVRs.

A standard DVR is about the size of DVD player.  The front of the DVR has buttons and switches to control the actions of the DVR.  The back of the DVR is where all the connections are made to cameras and other items.

A typical DVR has space for at least one hard disk drive; some have room for 3 or more plus a CD/DVD writer.  Like the camera, the DVR has Integrated Circuit (IC) chips dedicated solely to digital imaging.  These chips are known as Digital Signal Processors or DSPs.  Most standard DVRs these days also come with several other features that may or may not take up more space inside the DVR.

The DVR’s recording and storage unit is the “hard drive” also known as a Hard Digital Drive or HDD.  This hard drive is a relatively large device when compare to things like IC chips.   The hard drive contains magnetic plates that are written on by a magnetic head.   Since the device is digital the only thing the disk contains is a series of 0s and 1s.

The hard drive actually spins the platters (disks) usually about 7200 RPM while the magnetic head does the writing.  These are great for storing large amounts of data. However they are very intricate as well.  The space between the magnetic head and the platter is less than that of the thickness of a human hair.  This typically means that these devices are very sensitive and were not designed to take a lot bumping, vibrating, and the like.

In contrast, micro DVRs are very small.  There are no moving parts on a micro DVR.  That’s because micro DVRs use RAM (Random Access Memory) memory instead.  There are no moving parts on micro DVR because they do use RAM type memory.  The data is saved on RAM which has no moving parts.

This used to make micro DVRs nearly impossible to own because of the incredibly expensive RAM memory storage devices that include SD cards, Flash thumb drives, mini SDs, etc.  However, great strides have been made in RAM memory technology and today it is not cost prohibitive to purchase an SD card with 8 gigabytes of storage room.

In addition, video images can be incredibly large.  That’s because a video image is really nothing more than a digital picture taken many times in succession in a short period of time.  Typically, smooth video is obtained by taking from 15 to 30 pictures a second.  Let’s consider how much memory would be needed for just one hour of uncompressed video.  Most photographs these days run about 1 megabyte in size so will use this figure for our calculation:

1 MB (per picture) X 30 pictures (also called frames) per second X 60 seconds in 1 minute X 60 Minutes = 108,000 MB for one hour of video

However technology has also greatly improved in another area as well.  In addition to storage the micro DVR and even a standard DVR normally compress the files by using a CODEC (COmpression/DECompression) utility.  A CODEC shrinks the size of the video file while maintaining high quality of the video itself.  It does this by using special mini programs called algorithms that save space by not repeating the same objects.   For example, if a picture is taken of a football game with the sky in the back ground, the sky usually doesn’t change it’s appearance much.  A CODEC only saves information for the sky one time there fore reducing the overall size of the video image.

Micro DVRs take advantage of this as much as possible to extend their recording times on the portable recording media.

Where are micro DVRs used?  You’ll most likely find micro DVRs on all small specialty cameras such as hidden or disguised cameras.  Some of these camera are so small they do not have the option of saving their data on portable media that can be removed and replaced.  These cameras usually have a USB patch cord that they connect to almost any computer to download their files so they can be watched on the computer.

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