Visual Plane
every picture states the point it is correct from
Concept

Telephoto compression — where it appears

The flattened look of a long-lens picture, which is a consequence of where the camera stood rather than of the lens.

Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.

3 m, 50 mm1.50 m, 25 mmsubject ×1.000000 · background ×0.526 · zoom alone would give ×1 for bothnear-to-far ratio 10.00 → 19.00changing the focal length leaves it at 1.000000000000

Stepping closer is not zooming

Changing the focal length leaves the ratio between any two things in a picture exactly alone — to twelve decimal places, at every focal length there is. Moving changes it. Hold the subject's drawn size across a step from 3 m to 1.5 m and the background halves, which is the whole of the shot everybody knows and nobody derives.

sensor · dollyzoom isometric — the limit2.5 m6 m20 m200 msame box, same drawn sizethe eye recedes

The eye taken to infinity

A parallel projection is a photograph from infinitely far away with the lens lengthened to match. That is not an analogy — it is the limit, it can be watched happening, and it explains why a long lens flattens a scene and why an isometric drawing has no viewing distance to state.

parallel · limit

Named alongside it

The objects these essays reach for when they reach for this one.

Station pointViewing distanceCrop factorDemonstrationDepth compressionDepth cueDiminutionfield of viewFocal lengthForeshorteningIsometricOrthographic

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