Photographer's Reckoner
Photographer's Reckoner, a small reckoner that computes in your browser and stores nothing. No account, no cloud, no telemetry.
This is not a screenshot. It's the real tool, running right here: go on, put something in it.
Forged into a knife, this tool ages with use: the blades you reach for wear soft, entries you tend keep their bloom, and the years travel with the file through every reforge.
Photography is the art of light and the arithmetic of stops, and out in the field the arithmetic part has terrible timing. The Photographer's Reckoner does the exposure maths — the trades between the settings that decide what your sensor sees — while the light you are trying to catch is still there. It computes and stores nothing; the only record of the evening is the photograph.
Standing facts
- One HTML file. Opens in any modern browser, on any operating system.
- No account. No login, no sign-up, no e-mail wall.
- No cloud. Nothing leaves your browser: no server, no telemetry, no analytics.
- Yours forever. The file keeps working whether or not Offline.Ltd does.
- Ages with use. Entries you tend keep their bloom; the years travel with the file through every reforge.
In ten years
Photographer's Reckoner computes; it doesn't hoard. Open the file in 2036 and it will do the same arithmetic it does today, because the arithmetic is written into the file and nothing about it needs a server to agree.
If Offline.Ltd closes tomorrow, nothing on your machine notices. That isn't a marketing promise; it's simply what a file is.
Getting your data out
There is nothing locked in to get out: copy the numbers, or keep the file. Either way you owe no one a request form. No export queue, no "we'll e-mail you a link within 48 hours", no format that only one vendor can read.
Copy the file to a USB stick, a NAS, a folder your devices already sync. It runs on Windows, macOS, Linux, Android and iOS, online or off, because a browser is the only thing it ever needed.
Who else sees this
Nobody. Photographer's Reckoner works out its answer in your browser and forgets it the moment you close the tab: there is no store to breach, because nothing is stored. There is no account, no telemetry, no analytics, and no code in the file that opens a network connection, pull the cable and watch it carry on working. How privacy works across the Reckoners tools →
Questions people ask
What does a photography exposure calculator actually do?
It does the stop arithmetic between your settings, so when one side of the exposure changes you know exactly what the other side must do. The maths you can do slowly at a desk, it does instantly on a hillside.
Does it work in the field with no phone signal?
That is its natural habitat. It is one HTML file running offline in your browser — it computes on the spot, stores nothing, and never needs a connection. Nothing you calculate leaves the page.
Who is the Photographer's Reckoner for?
Film shooters, long-exposure landscape people, and anyone who works in manual and would rather trust arithmetic than luck. If your camera does everything for you, you may never need it; if it does not, you will.
Go deeper on Photographer's Reckoner
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Fits your knife at weight 1. Nothing here is final, Knife follows Life. Reforging within your tier is free, forever. Add it, drop it, reforge it later; the file stays yours either way.