FAQ

• For 1/3" CCD chip camera, the following formula is a simple way to determine the focal length of a lens needed.

  (Distance to subject / Width of subject) x 4.5mm = Focal Length. For example, if you want to watch a subject of 5.5ft width at 10ft distance with a 1/3" CCD camera, you will need a 8.0mm FL lens. That is, 10ft / 5.5ft x 4.5mm = 8.18mm. A 8.0mm FL lens mounted on 1/3" CCD camera will cover the subject you want to watch.

• <More details>

  Focal Length (FL) is the distance from the center of a lens to the focal point (CCD sensor chip). FL, as well as the CCD chip's format, is the major factor to determine the angle of view of a lens. For example, a 6.0mm FL lens on 1/3" sensor format has 56.8 degree of diagonal angle of view and a 5.0mm FL lens on 1/3" sensor format has 66.9 degree. But, the same 6.0mm FL lens can see 75.5 degree on 1/2" sensor format. The angle of view also varies a little depending on the Manufacturer of the lens.

• Angle of View

  The scene angle that a video camera lens can show on the monitor, like Diagonal Angle, Horizontal Angle and Vertical Angle, usually described in degree.

• Analogue

  Continuously variable numerical values such as voltage, current, etc. (The CCD camera produces analogue video signals.)

• AGC

  The video signal is amplified at low light levels by an automatic gain control circuit. Unfortunately noise is also amplified. In some cameras the gain level can be controlled manually. (MGC = manual gain control).

• AC Power

  Alternating Current Power. In the United States, the standard AC Power is single-phase 117VAC/60Hz and is provided from power outlets in the house. 24V AC power can be produced from an AC Adapter.

• 24VAC

  About two thirds of the professional cameras work with 24VAC, 20VA to 40VA. The cameras usually have screw type connections and you don't need to worry about the polarity. This power is usually supplied with AC Adapter and you need to prepare separate power cable for the connection. Unlike 12VDC, this power can be transmitted to a long distance up to 450ft and is proper for the cameras that are to be installed out-door or when you don't have the power outlet near the camera.

• 12VDC

  Most board cameras, mini cameras and about one third of the professional cameras work with 12V DC 100mA to 200mA for B/W cameras and 150mA to 300mA for color ones.

• AC Adapter

  Alternating Current Adapter; when plugged to AC Power (usually 117VAC/60Hz in the United States) it produces 12VDC, 24VAC or others. "UL Listed" and "Regulated" recommended. It is also called Power Transformer.