cone of vision — where it appears
Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.
Also named here as marginal distortion — the same set of essays touches all of them, so they are one junction rather than several.
A wide field on a small screen
A picture rendered at a hundred degrees and shown on a screen that subtends forty-nine is being read from two and a half times its own station distance, so the depicted space is two and a half times too deep. The stretch at the edges everybody complains about is correct; the complaint is really that nobody is sitting where it would be invisible.
The sixty-degree cone of vision
Every book says keep the subject inside a 60° cone. Measured, the marginal stretch the rule is nominally about is exactly zero from the station point — 1.000000000000 to 1, over 720 sampled points. The rule is a statement about the reader, and books do not obey it.
Named alongside it
The objects these essays reach for when they reach for this one.
field of viewMarginal distortionStation pointViewing distanceDemonstrationDepth compressionEdge stretchSubtended angleViewing position