Nowadays some problems encountered at the time of installation does not correspond only to the difficulty of passing wiring or the proper equipment configuration problems. Sometimes even if you previously designed a note disappointment compared to the lens or angle presented by that camera, always ending in a comment “Could get a little bit more of that area right?”, or even “the angle is open too much as well that could focus more on that door “, and with this, resulting in Exchange for equipment or even in Exchange for equipment position that still is more laborious.
To prevent this problem, especially in large areas that might require an adjustment after installation “there are varifocais/professional cameras, those cameras allow the user to adjust the opening angle of the image until it reaches the ideal focus for that area.
To understand better analyze below the difference of focus as the change of the lens on a camera. Follow the illustration:
In relation to the Integrated Circuit Television (CCTV) there are various types of dimensioning of lenses (3.6 mm, 6 mm, 12 mm, etc …), which differs from a lens on the other is your ability to adapt to the environment, being evaluated the lens of greater precision to the desired activity.
It is noteworthy that the value of the distance that the object of focus is in relation to the camera is of great importance for the choice of the lens.
Ex: In an elevator where it requires a recognition of the individual, you can use a lens 2.8 mm, whereas the distance of the object and the camera are smaller than, for example, in a long corridor where the door is located 20 meters from the camera.