Excellent picture quality in spite of difficult lighting conditions © iStockphoto.com / vicnt

Excellent picture quality in spite of difficult lighting conditions

State-of-the-art cameras are more light-sensitive than the human eye. Day-and-night cameras have different options for electronic image optimization and even provide usable images at night in black/white mode. Cameras with particularly high-quality sensors and additional functions are recommended if the objects are subjected to extremely fluctuating light levels, or if automatic motion detection is needed.

Electronic lighting compensation where there is strong backlight

Strong backlight impacts on the quality of the surveillance image, for example, if the camera is pointed from a building towards daylight outside. This results in overexposed image areas in which objects are difficult to recognize. Using an automatic shutter for backlight compensation also makes dark, blurred areas visible.

Cameras with a wide dynamic range (WDR) function have proven worthwhile for recording high-quality images where there is a backlight. Using WDR, dark and light areas are recorded separately from each other. The recordings are then electronically compiled into one evenly lit image.

For more information, go to our WDR page

Electronic lighting compensation where there is strong backlight © ABUS

Special image sensors for brightness compensation for conditions with high contrast

In certain locations, the camera's field of view is exposed to constantly changing and strongly fluctuating levels of light. For example, thanks to the moving position of the sun throughout the day, or the opening and closing of a door, the incoming light levels can change very rapidly from very dark to very bright.

For situations with highly contrasting light levels, particularly light-sensitive CCD image sensors (from Sony Effio, for example) and finely adjustable chip sets are suitable, which can adapt quickly to changed lighting levels and ensure exact electronic image optimization. This allows you to record clear-cut images, even at night.

Alternatively, you can use a camera with a Pixim CMOS sensor. Image sensors that use this technology regulate the light of each separate pixel separately and ensure optimal brightness compensation, and therefore good-quality images, particularly if there is high contrast.

Find out more about image sensors

Noise suppression for clearly recognisable details in poor light

In areas shaded by high trees or buildings, in narrow courtyards or entrances, there is often not enough light to obtain clear-cut images, for example in twilight. This results in strong image noise in video recordings. This noise makes it more difficult to recognize people, and impacts on automatic motion detection. It also uses up memory on the connected recording devices, as recorders interpret noise as image information.

Digital noise reduction (DNR) or state-of-the-art 3D DRR offers a solution to this problem. DNR cameras have very sensitive filters that separate noise from usable images, providing clear and sharp images.

Optimizing your video image

Changeover from daylight to night view

Most cameras cannot provide usable images at night. Day-and-night cameras, however, automatically switch to black-and-white mode when darkness falls. This mode is more light-sensitive and produces better results than colour mode. The automatic IR-cut filter that is installed in day-and-night cameras swivels away from the lens in night mode, so that the light from external infrared illuminators can also be used for night-vision recordings.
The optimal selection for night recordings may also be an IR day-and-night camera, in which the infrared illuminator is already integrated in the form of IR-LEDs. Make sure that the range of IR illumination is sufficient for your needs. Cameras with infrared illuminators are particularly recommended in indoor areas that are completely dark at night.

Find more ways to optimize your image quality

Changeover from daylight to night view © iStockphoto.com / IvanBastien

ABUS products for video surveillance in poor lighting conditions

  • Day/night cameras automatically switch over to black-and-white mode at low light intensities.
  • Infrared illuminators provide additional lighting that is not visible to the human eye.
  • Outdoor cameras with integrated IR-LEDs can be used not just in all weather conditions, but also at night.
  • Make sure that you are also using the correct lens: IR zoom lenses are compatible with infrared illumination.

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