Contact FocalMath

The fastest way to reach us is the email address below — it goes to a real inbox we check regularly, not a ticketing system. A few categories of message are especially useful to us and we read them first.

Corrections

If a camera spec, sensor dimension, or a formula's explanation looks wrong, tell us specifically what you shoot with and what number you'd expect instead. We'd rather fix a real error fast than leave it live because nobody flagged it.

Camera and Sensor Requests

The camera-body reference is deliberately a curated, bounded list of genuinely popular bodies rather than every camera ever made — if yours is missing and you think it should be on the list, say so and we'll consider it for the next update.

Calculator Feedback

If a calculator gave you a result that didn't match what you expected in the field, tell us your exact inputs and what you observed — sometimes that points to a genuine bug, and sometimes it points to a convention (like the circle-of-confusion divisor) that's worth explaining better on the page itself. Either way, that gap is useful for us to know about.

Everything Else

Bug reports, partnership or press questions, or anything else — the same address reaches us for all of it. We're a small operation, so response times vary, but every message genuinely gets read.