CCTV Knowledge 2 — Questions and Answers
Question 1: What does the term 'field of view' (FOV) refer to in CCTV systems?
- The maximum recording resolution of the camera
- The angular extent of the observable area captured by the camera lens (Correct answer)
- The depth of the camera housing
- The signal range of a wireless transmitter
Correct answer: The angular extent of the observable area captured by the camera lens
Field of view is the angular extent of the scene that a camera lens can capture, typically measured in degrees horizontally and vertically.
Question 2: Which IP camera standard defines interoperability between cameras and video management systems from different manufacturers?
- HDCVI
- ONVIF (Correct answer)
- H.265
- RTSP
Correct answer: ONVIF
ONVIF (Open Network Video Interface Forum) is the industry standard that ensures interoperability between IP-based security products from different manufacturers.
Question 3: What is the primary purpose of a video motion detection (VMD) feature in a DVR or NVR?
- To compress video files for storage
- To trigger recording or alerts when movement is detected in the video frame (Correct answer)
- To improve image resolution in low light
- To synchronize timestamps across multiple cameras
Correct answer: To trigger recording or alerts when movement is detected in the video frame
Video motion detection analyzes pixel changes within a video frame and triggers recording, alarms, or notifications when movement is detected.
Question 4: In CCTV terminology, what is 'dwell time'?
- The time a camera takes to adjust focus
- The duration each camera channel is displayed before the multiplexer switches to the next (Correct answer)
- The delay between motion detection and alarm activation
- The time required to back up recorded footage
Correct answer: The duration each camera channel is displayed before the multiplexer switches to the next
Dwell time is the length of time each camera image is displayed on a monitor before a multiplexer or switcher cycles to the next camera.
Question 5: What does 'WDR' stand for, and why is it important for CCTV cameras?
- Wide Dynamic Range — allows cameras to capture detail in both bright and dark areas simultaneously (Correct answer)
- Wireless Data Relay — enables cameras to transmit wirelessly
- Wide Distance Recording — extends the maximum recording range
- White Digital Resolution — improves image color accuracy
Correct answer: Wide Dynamic Range — allows cameras to capture detail in both bright and dark areas simultaneously
Wide Dynamic Range (WDR) technology allows cameras to produce clear images in scenes with both very bright and very dark areas, such as entrances with backlit subjects.
Question 6: Which cable type is most commonly used for traditional analog CCTV camera installations?
- Fiber optic cable
- RG-59 coaxial cable (Correct answer)
- Cat6 Ethernet cable
- RS-485 twisted pair cable
Correct answer: RG-59 coaxial cable
RG-59 coaxial cable is the standard cable used for transmitting analog video signals in traditional CCTV installations.
Question 7: What is the function of an OSD (On-Screen Display) menu in a CCTV camera?
- To display time and date stamps on recorded footage only
- To allow configuration of camera settings such as brightness, white balance, and exposure directly on the monitor (Correct answer)
- To overlay text alerts from the alarm system onto the video feed
- To switch between different recording resolutions remotely
Correct answer: To allow configuration of camera settings such as brightness, white balance, and exposure directly on the monitor
The OSD menu allows installers and operators to configure camera parameters like brightness, contrast, and white balance directly through the camera's video output.
CCTV Knowledge 2
What does the term 'field of view' (FOV) refer to in CCTV systems?