Buying Security Cameras : A Beginner’s Guide

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Buying Security Cameras A Beginners Guide
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• Security cameras are no exception and in fact,
  the many different specifications and functions
  available quite often confuses the average buyer.
  As this is a guide made for the
  not-so-technically-inclined, we wont bore you
  with the details about how the image sensors
  absorb light and transfer them into electronic
  signals or how TV lines are related to bandwidth.
  Instead, we bring you the meat, the details, and
  important facts you can use.

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1. Image Sensors

• CMOS
• Uses only 1/5 to 1/10 as much power as CCDs
• Cheap due to low cost of production
• Great for battery-powered wifi cameras
• CCD
• Less electronic noise than a CMOS
• Better image quality
• Super HAD CCD
• Twice as sensitive as traditional type of CCD
• Has a 6 db better smear rejection ratio than the
  formal traditional type of CCD

• Interline CCD
• High resolution
• Large pixels for high sensitivity
• High frame rates with multiple outputs
• Fast line dump for faster sub-sampling
• Low image lag and smear
• Great for machine vision, microscopy,
  fluoroscopy, and other applications that demand
  high imaging performance.

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• In the end, which is best? You might quickly vote
  for the Interline CCD, and you might be right,
  but recent advances in technology have minimized
  any quality differences between CMOS and CCD, so
  to a beginner I would say Its pretty much the
  same since image quality does not solely depend
  on the image sensor. Look at the other
  specifications too.

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2. TV Lines

• TV Lines refer to the horizontal resolution
  measured in relation with the pictures height.
  That is, for a standard 43 aspect ratio, your
  720 pixels accross the screen divided by 4/3
  would give a max of 540 TV lines in theory. Of
  course, it depends on the lens, the ccd, the
  camera output direct to a monitor, etc. The
  important thing to know is The more the better.
• Causes for low TVL
• A poor quality or badly set-up camera.
• A poor quality or poorly focussed lens.
• Poor quality video cables. These can cause
  distortion of the high frequency analog signals.
• The network bit rate used to transmit the video.
  If the bit rate is too low then TVL will be
  reduced.
• Product quality. Poor design of the analog to
  digital conversion electronics can greatly reduce
  TVL.

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3. Wired/Wireless

• There are many reasons to choose wired security
  cameras and many reasons to choose wireless
  security cameras. When making that decision,
  there are plenty of factors to consider the size
  of your home or property, the placement of the
  cameras, the cost, even weather and network
  interference. Wireless security cameras with long
  signals are very convenient because you can place
  them in many different, hard-to-reach spots,
  without worrying about wires or cords. The
  signals can also go up to 1000 feet, which means
  you can have your wireless security cameras in
  areas that didnt have the proper outlets for
  regular wired security cameras. Wired security
  cameras, on the other hand, tend to be more cost
  effective. You never have to worry about dropping
  the signal or worry about obstructing or
  otherwise affecting the wired security cameras
  signal. One is obviously not inferior to the
  other, there is only one better for your needs.

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4. Useful Features

• Waterproof/Weatherproof
• Night Vision
• Motion Detection and Alarm Settings
• Pan, Tilt, and Zoom

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Thank You

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