CCTV Video Surveillance System Design 3 — Questions and Answers
Question 1: What is the recommended minimum resolution for a camera intended to capture license plates at a distance of 50 feet?
- 480p (SD)
- 720p (HD)
- 1080p (Full HD) or higher (Correct answer)
- Any resolution with good night vision
Correct answer: 1080p (Full HD) or higher
License plate capture at distance requires high resolution (1080p or higher) to provide enough pixel density for legible plate identification.
Question 2: When designing a system to minimize storage consumption without sacrificing critical footage, which recording mode is most appropriate?
- Continuous 24/7 recording at maximum bitrate
- Motion-triggered recording (Correct answer)
- Scheduled recording during business hours only
- Manual recording initiated by the operator
Correct answer: Motion-triggered recording
Motion-triggered recording activates only when movement is detected, dramatically reducing storage use while preserving all relevant events.
Question 3: Which lens focal length provides a narrower field of view and greater magnification for distant subjects?
- 2.8mm
- 4mm
- 6mm
- 12mm (Correct answer)
Correct answer: 12mm
Longer focal lengths (12mm) provide greater zoom and magnification but a narrower angle of view, making them ideal for monitoring distant areas or entry points.
Question 4: What is the primary advantage of using a varifocal lens camera in system design?
- It automatically adjusts to IR illumination
- It allows the installer to adjust the focal length to match the coverage area (Correct answer)
- It eliminates the need for a DVR
- It provides 360-degree coverage
Correct answer: It allows the installer to adjust the focal length to match the coverage area
Varifocal lenses can be manually or motorized-adjusted to a range of focal lengths, giving installers flexibility to optimize field of view after mounting.
Question 5: A client wants full perimeter coverage of a rectangular warehouse with four corners. What is the minimum number of cameras needed if each has a 90-degree FOV?
- 2
- 4 (Correct answer)
- 6
- 8
Correct answer: 4
Four cameras, one at each corner aimed diagonally, each covering 90 degrees can cover all four sides of a rectangular perimeter with no blind spots.
Question 6: What does WDR (Wide Dynamic Range) technology do in a camera, and when is it most needed in system design?
- It increases wireless transmission range for IP cameras
- It balances exposure in scenes with both very bright and very dark areas (Correct answer)
- It doubles the camera's frame rate in low-light conditions
- It encrypts the video feed for secure transmission
Correct answer: It balances exposure in scenes with both very bright and very dark areas
WDR technology combines multiple exposures to produce a properly exposed image when a scene contains extreme contrast, such as a bright doorway with a dark interior.
Question 7: In designing a retail store CCTV system, which area typically requires the highest camera density?
- The storage room
- The point-of-sale (POS) and checkout area (Correct answer)
- The emergency exit corridor
- The employee break room
Correct answer: The point-of-sale (POS) and checkout area
POS and checkout areas are high-theft and fraud zones, requiring close-up coverage of transactions, cash handling, and customer-employee interactions.
CCTV Video Surveillance System Design 3
What is the recommended minimum resolution for a camera intended to capture license plates at a distance of 50 feet?