What is Dynamic Range?
Electronic sensors such as CCD and CMOS devices are continuously evolving. One of the biggest challenges in surveillance cameras is dynamic range. In this case we refer to dynamic range as the range of light level from the darkest part of the image to the brightest part which can be captured by a camera. The human eye can perceive up to 113dB, however even the best CMOS sensors available today can only capture 60dB. To understand what this means in real applications, 60dB could be equivalent to the range of light level in an office or corridor with no direct sunlight as seen below.
Wide Dynamic RangeIf we introduce sunlight though a doorway or window, the range rapidly extend up to 113dB and beyond, with very bright and very dark areas in the same scene. This results in darker areas being represented as black, and lighter areas as white losing image information in those areas.
To address this problem many manufacturers introduce wide dynamic range technology. This technology extends the dynamic range of the image, using various technologies which can compromise image quality or frame rate.
Introducing View-DRView-DR uses an electronic shutter to capture multiple images at different exposures, these are combined in real time to produce each wide-dynamic video frame. One image is taken using a standard exposure time; an additional 1-3 images are taken using progressively shorter exposure times (depending on models and View-DR settings). The resulting image is processed by a technology called Visibility Enhancer to further improve the chrominance and luminance, resulting in natural looking, wide dynamic images even better than the naked human eye can perceive. With the W Series, Full HD models can achieve a dynamic range of 130dB, almost double that of conventional wide dynamic range technologies.
The Benefits of View-DR Technology
Security cameras must offer natural and clear image reproduction in any environment 24 hours a day, 7 days a week. They must provide clear images in continuously changing lighting environments, from strong sunlight with high contrast, to low light & low contrast.
View-DR works dynamically, continuous adapting to the lighting conditions with no calibration or alignment required, providing an optimum image at up to 30fps (60fps on some IPELA Engine models). The IPELA Engine platform takes this technology a step further, supporting high frame-rate mode, providing 90dB wide dynamic range at up to 60fps.