Jones diagram

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A Jones diagram is a type of Cartesian graph developed by Lloyd A. Jones in the 1940s, where each axis represents a different variable. In a Jones diagram, unlike in a Cartesian graph, the +X and -X (and +Y and -Y) axes represent different quantities, not positive or negative intensities of the same quantity. The diagram therefore represents four variables, where the first depends on the next, which depends on the next, and so on. The overall system response is in quadrant I; the variables that contribute to it are in quadrants II through IV.

[edit] Jones diagrams in photography

FIG. 1 from U.S. Patent 6,484,631.
"a graphical illustration of a Jones Diagram for calibrating user specified tone reproduction curve (TRC)"

A common application of Jones diagrams is in photography, specifically in displaying sensitivity to light with what are also called "tone-reproduction diagrams." These diagrams are used in the design of photographic systems (film, paper, etc.) to determine the relationship between the light a viewer would see at the time a photo was taken to the light that a viewer would see looking at the finished photograph.

The Jones diagram concept of variables that depend successively on each other can be extended to more than four variables by printing each quadrant separately. Jones's original diagram used eleven quadrants to show all the elements of his photographic system.

[edit] References

Walls, H. J. & Attridge, G. G. Basic Photo Science. London: Focal Press Ltd., 1977. ISBN 0-240-50945-5

[edit] External links

Example of a motion-picture film Jones diagram
Example of a CRT Jones diagram: US5,371,537 (PDF version) (1994-12-06) Bohan, et al. Method and apparatus for automatically calibrating a CRT display .