Lenses for network video cameras

Conclusion

  • Different applications are often best served by selecting a particular type of lens, i.e., a fixed focus lens, or a zoom lens that offers multiple fields of view without the need to refocus.
  • An iris can be fixed or adjustable, and in the latter case, the control can be manual or automatic.
  • Automatic iris control (DC-iris or video iris) is achieved by using the light level to send a signal to the motor controlling the iris. A P-iris uses the same principal, but also involves special software for very precise control, as well as preventing the iris from closing too far.  
  • The C-mount and the CS-mount are the most common standards today in network cameras.
  • The i-CS lens contains information about its own properties, which is read and used by the camera to optimize image quality and to offset barrel distortion and unstable video.
  • The i-CS lens is a major step forward in lens technology, providing methods for automatic control of focusing and iris opening. The communication between lens and camera uses a freely available protocol, allowing other manufacturers to develop other compatible lenses and cameras.