Choosing a security camera system requires a few basic decisions. Here are some questions to help guide your purchase:

• How many cameras will you need? Some monitoring systems can accommodate only one or two, while other systems offer further expansion.
  
   
• Do you need audio as well as video? Some camera systems include microphones so you can hear what you're seeing.
  
   
• Do you want color or black and white? Color pictures are often clearer, but the equipment can be more expensive. Color cameras might not work in low-light situations.
  
   
• Do you prefer wired or wireless? The right choice for you depends on where the camera will be located:
  
   
  • Wired cameras are fixed in place and must be put in a spot where the wiring won't get in the way. They offer greater assurance of a high-quality picture.
    
     
  • Wireless cameras can be moved around easily and can be installed in more places, but other devices (such as cordless phones, baby monitors and some computer networks) can interfere with signal transmission.
    
     
• Will the camera be outside? Cameras that monitor outdoor locations require special weatherproof housings and may not be appropriate for extreme temperatures. Those that might be the target of vandalism need extra-tough casings to resist tampering.
  
   
• What is the light source? Steady, reliable light — either from the environment or from the camera itself — is required for clear images. A camera's lux rating measures its ability to capture images in the dark. The lower the lux rating, the less light is required for a clean picture. Unobtrusive monitoring in the dark or near-darkness can be done with infrared light, which is invisible to the human eye, but the technology can be expensive.
  
   
• Is there a power source nearby? Some cameras and monitors must be plugged into a wall outlet. Others can run on battery power.
  
   
• Do you want to use your computer? Some cameras can be attached to a computer, allowing you to view the images from anywhere using an Internet connection. The required software is usually included with the camera.
  
   
• Will you record the images? Some cameras are meant just for viewing — to see what the kids are doing in the backyard or who is ringing the doorbell. Others are meant for long-term monitoring and may be attached to VCRs. If a VCR attachment is planned, make sure the camera system is compatible with the recorder. Special VCRs can use time-lapse recording to fit many hours on a standard videotape. Some recorders can be set to activate only when motion is detected.

Wireless systems may include portable cameras that can be moved around without permanent installation. Take care that nothing between the camera and the monitor degrades the signal that is transmitted. Cordless telephones, baby monitors and some home computer networks may cause interference.