Chapter 2: Camera Technologies
From EZWatch Wiki
The Different Camera Technologies
Indoor Cameras:
Indoor cameras come in all types, sizes and styles. The most popular is the smoked mini dome camera. The dome camera can be mounted on the ceiling or wall and adjusted to view any angle. Although the dome is designed to protect the camera inside, they are not weather tight and should not be installed where they are exposed to moisture or extreme temperatures.
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Outdoor Cameras:
The only difference between indoor and outdoor cameras is that the outdoor cameras are in an environmentally protected housing. Some housings have heaters and blowers to keep the temperature inside within the operating parameters of the camera. Others such as the mini outdoor bullet cameras generate their own heat for operation. All outdoor cameras discussed in this guide are designed to operate in -10 degrees to 120 degree temperature.
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Day/Night or Night Vision:
Affordable night vision cameras are the latest innovation to the video surveillance industry. There are many types and styles to choose from but they all have one thing in common, infrared LED's. Small LED's that transmit out infrared light surround the cameras lens. The LED's cast out light the camera can see but the human eye cannot. The distance a camera can see in the dark is based on how many LED's the camera has. As a rule a camera with 10-20 LED's can see 20 feet in complete darkness. Some cameras such as the one below can see up to 70' in complete darkness. Notice the LED's surrounding the camera lens.
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These cameras provide high quality color pictures during the day and when the light levels drop past a minimum level, they automatically switch to night vision or black and white pictures in complete darkness. When the light levels increase the camera automatically changes back to color video. These cameras are very reliable and flexible and should be considered when designing your system.
Low Light Cameras:
Low light cameras are color cameras which need very little light to operate (.1 lux). They work well in most applications but they do require some lighting, similar to the lighting provided in a romantic restaurant.
Hidden Cameras:
Because cameras are so small now they can be hidden in almost anything. It's common to see cameras in pictures, clocks, radios, smoke detectors, motion detectors, books, ties and anything else we can dream up. The cameras are the same cameras used with standard indoor cameras. The only difference is the housings used.
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Pan Tilt Zoom Cameras:
PTZ cameras, as they are called, are considered "top of the line" in security cameras. They can pan 360 degrees, tilt 270 degrees, and optically zoom in as much as 22 times. They are controlled and programmed with either a desk top joy stick control or through the software of a PC based DVR. They come in both indoor and outdoor versions, can be wall or ceiling mounted, and can be equipped with color Day/Night cameras or night vision.
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The cameras can be programmed to automatically run preprogrammed tours, automatically panning, tilting and zooming to predetermined locations. They can also be programmed to pan, tilt and zoom to a specific view if motion is detected or a pre-defined alarm occurs. A user can override the automatic operation and control the cameras as needed. Up to 16 PTZ cameras can be installed on most DVR systems (as long as the DVR supports 16 cameras). The cameras are controlled with a two wire communication wire which loops from one camera to another. Each camera has dip switches which are used to set its address. The comm. wire can have a maximum distance of 3000 feet. In addition to the communication wire each camera also required a video cable to transmit the video signal back to the front end.
On DVR's the communication cable terminates on a PTZ Netcom control board installed in the DVR. This control board interfaces the software and mouse commands with the cameras. On time lapse and other systems the cameras are controlled with a desk top joy stick control. One down side to the joy stick control is it does not provide the ability to control the cameras remotely.
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The average cost of a good PTZ camera is $1,300 to $2,000. When you consider a PTZ camera can only see in one spot at one time, you may want to consider installing multiple fixed view cameras for the same or less money.
Wireless Cameras:
We have been very careful about recommending and supporting wireless products. In the past wireless security cameras have been notoriously unreliable and seldom meet the expectations of the consumer. However, with the development of wireless networks and IP technology, new products have emerged which do provide a level of performance acceptable for small and mid-sized video surveillance applications. This new technology uses a Digital "Spread Spectrum" technology which provides reliable wireless video transmission up to 300 feet and secures the video signal so it can not be viewed by others outside the building or home.
The following chart details the main differences between the old wireless technology (2.4 Ghz - Analog) and the new technology (2.4 Ghz - Digital):
| Performance Comparison | 2.4 Ghz - Analog (Old) | 2.4 Ghz - Digital (New) |
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| Cost Per Camera: | $69- $149 | $250 - $700 |
| Average Transmission Range: | 10 - 30 Feet | 150 - 300 Feet |
| Reliability: | Poor | High |
| Video Quality: | Poor to Standard | High |
| Transmission Speed: | 10-20 Images Per Second | 20-30 Images Per Second |
| Signal Security: | None | Excellent |
| Available Channels: | 4 Max | Unlimited |
| Pan/Tilt/Zoom Control: | No | Yes |
| Non Centralized Viewing: | No | Yes |
| Internet & Web Access: | No | Yes |
| Viewing: | Analog TV Monitor | PC - Computer |
2.4GHz - Analog Cameras
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| Back to Chapter 1 | Return to Overview | Continue to Chapter 3 |
