The need for crisp and clear video images in low-light environments always exists. The data confirms it: when committing crimes like burglary and vehicle theft, criminals definitely prefer to hide under the cover of darkness. So to both prevent and tackle crime, it’s vital to have security cameras that can record quality, discernible footage in a variety of light conditions, especially in near-total darkness.
For years, improvements in sensor technology and algorithms to enhance the image have helped deliver better surveillance in low-light conditions. Besides IR illumination, other availabilities include the addition of visible light in the vicinity of the field of view, the use of image intensifiers, low-light lenses, and thermal cameras. In this blog, different types of cameras – including some of the latest Hikvision technologies – will help one understand the workarounds for low-light and pitch-black monitoring.
Low light means anything down to 0.002 Lux – that’s the same conditions as a moonless, clear night. Many surveillance cameras built for low-light performance can deliver usable and high-quality images by applying better optics and advanced sensors. To put it simply, the lens used thereby gets as much light as possible onto the image sensor. With this approach, Hikvision offers two options.
The first is the Hikvision ColorVu range of cameras, which is ideal for monitoring at a closer range. With an F1.0 super aperture and an advanced sensor, these intelligent eyes pull in four times the light of a conventional camera, for daylight-like colour images in low-light conditions. Should light levels fall to zero, the built-in warm supplemental lighting ensures the camera can still capture vivid colour images within up-to 40 metres range.
If one needs low-light security monitoring over larger distances, then the Hikvision DarkFighter camera range is ideal. Featuring a large-sized progressive scan CMOS sensor and a DarkEye SLA lens with a super large F0.95 aperture, DarkFighter cameras can deliver excellent HD high colour images down to 0.002 Lux.
The camera’s increased field of view allows security operatives to pan around and cover a large area of attention, particularly ideal for city streets monitoring, and open environments like ports, squares, parking lots, etc.
When there is zero ambient light, there is one industry-standard option: Infra-Red Cameras. Security camera manufacturers have created true day/night cameras that add IR illuminators to capture monochrome images when the light level falls to zero lux. Specifically, IR illuminators emit infrared light that is reflected by objects and is further collected by the camera sensor to produce a sharp, black and white image.
The vast majority of cameras on the market come with built-in IR illuminators. But if one wants to take things a step further, it’s worth considering the Hikvision DarkFighterX camera range. Based on the human eye, these cameras use a single lens featuring two sensors: one for IR imaging – ensures that video footage is bright and sharp, and the other for visible light – which allows video images to be reproduced in full and vivid colour. Both signals work together to create a single, bright, full-colour image in light conditions as low as 0.0005 Lux. In zero light, the cameras enable the mixed supplemental lighting to render colour images.
There is a solution even if it’s pitch black, and the view is obscured by rain, fog or even thick foliage. If one is trying to see in the most challenging of conditions, there’s one trusty option: Thermal Cameras. Rather than using light, thermal cameras measure heat – or thermal radiation – to generate images from their field of view. In this way, the rendered image is far less affected by rain, snow, fog, smog or indeed anything that can obscure light.
The way thermal cameras “see” allows them to pick up movements with high accuracy, giving security operatives eyes on objects, vehicles and intruders. Combined with Video Content Analysis (VCA) technology, thermal cameras can offer a range of perimeter security solutions, such as line-crossing detection and intrusion detection. This means they can easily detect intruders moving through bushes or under the cover of complete darkness.
Hikvision offers a range of cutting-edge thermal cameras, including those that deliver the best of both worlds: Bi-Spectrum Cameras, which combine thermal and optical images to create a hybrid image, making it easier to find hidden objects and document unusual events.
