APERTURE, SHUTTER, ISO

one stop is twice the light: three scales with the same step on each

Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.

Three sizes in one archive — from a sheet on the fridge to a poster on the wall.

Formats: A4 · A3 · A2
What you get: Print-ready PDFs, one per size, with every letterform converted to outlines — nothing to install, nothing to shift.
Subject: units · everyone · memo · study

At the top are the openings of one lens, each half the area of the one to its left. In the table the large figure is what the camera prints and the small one beneath it is the exact value; the cells where the two differ are set in colour. At the foot is what actually changes when a stop is handed to a neighbouring scale.

THE NUMBERS ON THE CAMERA ARE ROUNDED, AND THAT IS FINE

The numbers on the ring and on the dial are roundings, not the doublings themselves. f/11 ought to be f/11.3137 and passes 5.8% more light; 1/15 ought to be 1/16 and lasts 6.7% longer.

But the error never accumulates. Each mark is rounded from its own exact power rather than from its neighbour, so the scale returns to the exact value at every second stop: f/16 is exactly 16. Across the whole scale the largest miss stays under a tenth of a stop.

On the sheet

At the top are the openings of one lens, each half the area of the one to its left. In the table the large figure is what the camera prints and the small one beneath it is the exact value; the cells where the two differ are set in colour. At the foot is what actually changes when a stop is handed to a neighbouring scale.
Colour carries meaning, but meaning never rests on colour alone — the sheet reads in black and white.
Nothing about how it was made: the sheet carries only what the reader needs.

Printing

Three sizes in the archive: A4 — 210×297 mm, A3 — 297×420 mm, A2 — 420×594 mm.
All text is converted to outlines. No fonts to install, and nothing shifts on another machine.
White background and sparing fills — it prints on a home printer without draining the cartridge.
Margins of at least 10 mm: a home printer cannot print to the edge.
No stroke thinner than 0.3 mm, so nothing disappears in print.

Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 8 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.

APERTURE, SHUTTER, ISO

THE NUMBERS ON THE CAMERA ARE ROUNDED, AND THAT IS FINE

On the sheet

Printing

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