General Video Surveillance Questions

Question: What is the difference between CCD & CMOS Cameras?

Answer: Briefly speaking, CMOS cameras are better in close-up areas for basic observation, and typically cost less, where CCD cameras have a wider view angle, lower lux rating, and sharper picture.

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Question: Where can I find manuals for my surveillance system?

Answer: All on-line surveillance manuals are listed on the Index to Home Alarms page.

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Question: What is a "cone angle", "viewing angle" and "definition angle"?

Answer: All three terms refer to the same specification, which indicates the maximum angle that the camera can see. The angle represents a three-dimensional cone extending from the camera, as shown in the illustration at right.

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Question: How much area will a camera with a viewing angle of 72° / 90° / 110° actually see?

Answer: The following information provides a general approximation of the viewable area for the three view angles:

View angle of 72°

1.5 X Distance away from object ≤ Viewable area

For example, if the camera is 10' away then the camera will view an area ≤ (less than or equal to) 15' across (left to right).

1.5 X 10' away ≤ 15' viewable area.

View angle of 90°

2.0 x Distance away from object ≤ Viewable area

For example, if the camera is 10' away then the camera will view an area ≤ (less than or equal to) 20' across (left to right).

2.0 x 10' away ≤ 20' viewable area.

View angle of 110°

3.0 x Distance away from object ≤ Viewable area

For example, if the camera is 10' away then the camera will view an area ≤ (less than or equal to) 30' across (left to right).

3.0 x 10' away ≤ 30' viewable area.

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