New Delhi, Sept. 2 -- A CCTV camera can look impressive on a product page and still struggle when the lights go out. At night, image noise, motion blur, glare and reflections can make it difficult to identify a person or vehicle, even when the camera claims high resolution and long-range night vision. If you are buying a security camera for your home, the question is not simply whether it has night vision, but what kind of night vision it uses and how well it suits the place you want to monitor.

Most night-vision cameras do not "see in the dark" in the same way our eyes do. Instead, they either add their own illumination or make better use of the small amount of light already available.

The most common approach is infrared (IR) night vi...