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A dynamic range in an image is the number of intensity levels there are between light and dark areas. In high dynamic range imaging, the general idea is to form an image that appears as realistic as the human eye sees it. Light and dark contrast can comprise of sunlit areas and parts of a picture where there are shadows cast. This kind of image processing usually involves the exposure of multiple images, which are processed by a computer program. With a technique called tone mapping, one image can be processed using a computerized map of colors to approximate a natural setting.
High dynamic range imaging can be accomplished by loading multiple versions of one picture into a computer. The light and contrast levels are altered by a software program which typically stores a source file to edit the final image. These files are generally large compared to traditional picture files, and can take a long time to process. Several commercial imaging programs can accomplish high dynamic range imaging, often by tone mapping to make the process suitable for novice users.
Working with high dynamic range imaging usually takes some experience with photography and computer software. There can be many steps to get to the finished image. Managing a few files at once is often necessary, which can lead people to inadvertently miss steps and make mistakes. The step-by-step process, however, can be learned with practice.
Powerful computer chips, incorporating light-sensitive sensors, are sometimes included in high-end cameras to enable high dynamic range imaging. There are some computer chips that have a series of high and low sensitivity sensors arranged in groups. Such chips, as of 2011, increase the dynamic range of the picture but do not create as high a resolution as some other products. Sensor chips could also become sensitive enough to low light levels that eventually cameras might not need a flash.
High dynamic range imaging is used in photography as well as computer graphics. Just the right contrast is often sought for realistic pictures. Computer renderings, however, can increase the dynamic range more than what looks realistic, but could be used to maximize detail. Often listed as a specification of screen quality, dynamic range generally affects the appearance of film, panoramas, or lighting effects in video games. It has improved in computer screens over time, and manufacturers could build high-definition monitors with larger dynamic ranges going beyond 2011.