Dynamic range
From Free net encyclopedia
Dynamic range is a term used frequently in numerous fields to describe the ratio between the smallest and largest possible values of a changeable quantity.
Examples of usage
Audio engineers often use dynamic range to describe the ratio of the loudest possible undistorted sound to the quietest or to the noise level, say of a microphone or loudspeaker. In digital audio, the maximum possible dynamic range is given by the bit resolution. See signal-to-noise ratio.
Electronics engineers apply the term to:
- the ratio of a specified maximum level of a parameter, such as power, current, voltage or frequency, to the minimum detectable value of that parameter. (See Audio system measurements.)
- In a transmission system, the ratio of the overload level (the maximum signal power that the system can tolerate without distortion of the signal) to the noise level of the system.
- In digital systems or devices, the ratio of maximum and minimum signal levels required to maintain a specified bit error ratio.
In audio and electronics applications, the ratio involved is often so huge that it is converted to a logarithm and specified in decibels.
In music, dynamic range is the difference between the quietest and loudest volume of an instrument, part or piece of music.
Photographers use dynamic range as a synonym for the luminosity range of a scene being photographed; the light sensitivity range of photographic film, paper and digital camera sensors; the opacity range of developed film images; the reflectance range of images on photographic papers. It can be controlled through the use of a graduated ND filter.
High Dynamic Range Imaging is an emerging field in computer graphics which seeks to represent light levels (either measured or synthesised) as an open-ended range of absolute values, rather than as a simple ratio of 'full' brightness. This allows more accurate and realistic renderings, as well as post-processing effects such as bloom.cs:Dynamický rozsah de:Dynamikumfang es:Rango dinámico fr:Portée dynamique (son) nl:Dynamisch bereik