Day & Night Video Quality Video Quality
Introduction This section will bring you through the following concepts about: 1. Basic concepts about how day and night cameras work. 2. How do cameras see at night.
Agenda ●How Do Day and Night Cameras Work? -- Day and Night Cameras -- Dual Profile ● How Do Cameras See at Night? -- Cameras VS. IR Light -- The Influence of IR light to Cameras -- Using IR Light for Night Vision -- Day & Night Cameras ● Tips for Night Video Surveillance
How Do Day and Night Cameras Work?
Black & White image Day and Night Cameras Color Image ● Daytime: Color image Nighttime: Black & White image ● Auto-switch between day and night CDS ● Mechanical IR cut filter Auto switch
Dual Profile As light decreases: ● Shutter speed↑ ● Iris↑ As signals increase: ● Frame rate↓ ● Bit rate ↑ What happens to the video during the night? Light Signal Dual profile Day mode Day profile; Night mode Night profile
How Do Day and Night Cameras See at Night?
● Infrared Rays (IR): IR light has a longer wavelength than visible light and is not perceived by the human eyes. Cameras VS. IR Light
Day time ( sufficient visible light) The Influence of IR light to Cameras Visible Light Only ● The sensor catches IR light, causing color distortion With IR light ● IR Cut filter -- Passes visible light -- Blocks IR light Color distortion! Sensor IR Cut Filter Visible light IR light Day time Night time
Using IR Light for Night Vision ! ● For certain security issues, visible light is easy to be noticed and evaded. ● For night vision, IR illumination allows operation even in complete darkness (0 lux) without being noticed by the human eye.
Camera with IR LEDs ● The use of IR illumination -- IR illuminators / IR LED built-in Cameras IR LED Zoom 1 zoom camera + 2 IR illuminators ● IR illumination helps the camera to see details for night surveillance video. Normal With IR Light
Tips for Night Video Surveillance Tip #1 Make sure your target area is well-lit with proper light. An IR LED built-in camera is always a good choice for total dark (0 lux) environment. Tip #2 Minimize the light pollution. In outdoor scenes, be careful not to point your night vision camera to another one or straight strong light sources, as they will could produce unwanted artifacts in the recorded video.