The Digital Fact Book - Quantel

DensityThe density (D) of a film is expressed as the log of opacity (O).D = Log 10 ODUsing a logarithmic expression is convenient as film opacity has a very wide rangeand the human sense of brightness is also logarithmic.See also: Film basics (Tutorial 2)Depth grading (Stereoscopic)A post production process where negative and positive parallax convergence are adjusted.This is not only a creative tool used to place objects on the Z axis but also a way to ensurethat stereoscopic content can be comfortably watched on the screen size it is intendedfor. For example, in a post suite the director may be viewing a film on a small projectionscreen but the final delivery format may be a large theatre or IMAX.In practice the eyes have little ability to diverge (up to one degree is considered the ruleof thumb) and this is especially a consideration in depth grading for very large screenswith positive parallax images, where the distance between the left and right representationsof an image may be very widely spaced.Sometimes the term Depth Budget is used to refer to the combined value of positiveand negative parallax and expressed as a percentage of screen width.See also: ParallaxDFSDistributed File System – used to build a hierarchical view of multiple file servers andshared files on a network. Instead of having to think of a specific machine name for eachset of files, users only need to remember one name as the key to a list of shared files onmultiple servers. DFS can route a client to the closest available file server and can alsobe installed on a cluster for even better performance and reliability. Medium-to-large sizedorganizations are most likely to benefit from using DFS while smaller ones should be finewith ordinary file servers.58