Jones diagram

In a Jones diagram opposite directions of an axis represent different quantities, unlike in a Cartesian graph where they represent positive or negative signs of the same quantity.

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.)

The Jones diagram concept can be used for variables that depend successively on each other.

Jones's original diagram used eleven quadrants[how?]

Two-quadrant analogue of a Jones diagram showing the relationship between a camera's focal length , crop factor and angles of view for two aspect ratios via its effective focal length – for example, the yellow line shows that 18 mm on 3:2 APS-C is equivalent to 27 mm full-frame and yields a vertical angle of 48°, and so on
FIG. 1 from U.S. Patent 6,484,631.
"a graphical illustration of a Jones Diagram for calibrating user specified tone reproduction curve (TRC)"