what are the types of cctv cameras?

egg york asked:


can u include the explanation and the differences in the types

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This entry was posted on Tuesday, April 14th, 2009 at 9:44 pm and is filed under Cameras. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

2 Responses to “what are the types of cctv cameras?”

1. bbsisxlii Says:
   April 17th, 2009 at 10:19 pm

   Camera Types:

   Fixed (non moveable) CCTV security cameras come in two main styles: The first style has a camera body, to which lenses of different focal lengths and/or fixed or variable irises may be attached. The factors involved in choosing a suitable lens are given on the CCTV Camera Lenses page. Features such as BLC (Back Light Compensation), Auto Iris Drive and AES (Auto Electronic Shutter) on/off are provided, as is availability in several power inputs (e.g. 12V DC or 24V AC). New technology cctv camerascameras now provide an “On Screen Display” (OSD) for choosing and setting functions. Because of their flexibility of configuration, body or box cameras are widely used in most commercial video surveillance systems.

   The second style is basically a fixed lens mounted on a camera circuit board (board camera). These cameras may be packaged in a small case (Mini Cameras) or dome (Mini Dome) or tube (Bullet, Lipstick or Tube) or simply sold unpackaged, for mounting by the purchaser. Lenses in these cameras are either of a normal industry aperture or a “pinhole” lens of very small aperture. Pinhole lens cameras are often called “spy” cameras and may be mounted in a concealed way for covert surveillance purposes. Since the lenses in board cameras are pre-mounted, have a fixed iris and are usually of a short focal length (i.e. wide angle), their flexibility of usefulness is limited. However, this type of camera can provide a low cost solution in the right situation, particularly in a home or retail environment.

   Pan, Tilt, Zoom (PTZ) Security Cameras: PTZ security cameras are able to rotate horizontally through 360°, vertically through 90° and have electrically powered zoom lenses capable of giving better than fifteen times optical zoom. Movement can be very fast and is controlled through a connected controller and/or through an appropriate DVR. In addition, PTZ cameras can be set to auto-scan or to move through a pre-defined range of pre-set positions and amounts of zoom.

   New advances in technology now provide digital zoom in addition to optical zoom; day/night light sensitivity; intelligent movement that prevents too much incrementalptz security cameras movement at bigger zoom factors and user definable movement “patterns” rather than guard tours consisting of numbers of presets.

   PTZ security cameras are normally mounted in domes and when used outside, the domes are weatherproof and thermostatically cooled and heated. Vandal resistant domes are also available.

   Once used almost exclusively by large corporations, governments and casinos, Pan, Tilt, Zoom (PTZ) CCTV cameras have now become much more affordable and offer better performance than just a few years ago.

   Have a blessed day!
   Be safe!
   -sentry

2. screwdriver Says:
   April 18th, 2009 at 10:22 am

   Have you got an hour or two? There are CCTV cameras for all situations and lighting conditions.

   The cheapest are CMOS low resolution ones, very insensitive and need good light.

   Then there are CCD cameras, much more sensitive, available in various resolutions.

   The resolutions start at 320 X 160 pixels and go up to 1024 X 768, there are specialist cameras that can go to 3Mp sensors.

   There are B&W and Colour versions in all these.

   Prices are just a few pounds for a B&W CMOS at 320 X 160 (these are the cheap ones you see on eBay, not very good) up to several thousand pounds for a colour CCD 3Mp type.

   Then there are variations in how they work, by far the majority are just like web cams with a continuous 25 or 30 frames per second output so as light fades the picture dims, but there are other types for low lighting that can alter their frame rate, in normal lighting they output at 25 or 30 fps, in dim lighting they output less than that, but they output a quality colour image everytime. They can go as far as one picture every few minutes when its too dark for you to see anything, there has to be some light, but that could be a 60W light bulb a 1/4 of a mile away!! They are designed to work by starlight, and still give a perfect colour image.

   Then there are Infra Red, most CCTV camera do not have an IR filter so are very sensitive to it. All IR cameras are B&W. Its possible to combine these with powerful IR sources (take loads of power and are expensive) so, to the camera it looks like daylight, but we can’t see it so to us its pitch black.

   These are not to be confused with heat sensitive cameras which are very expensive and a different technology.

   Then there are all the different housings available, hard drive recorders, motion detection, Pan Tilt and Zoom. You can couple them up to PIR (motion detectors) so any motion outside the cameras view will be detected and pan the camera to it and zoom into it automatically, perimeter detectors can do the same.

   Chris

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