ReciproMeter

Film reciprocity,
measured cleanly.

ReciproMeter is a privacy-first iPhone app for film photographers. Meter scenes with your camera, lock the reading, apply reciprocity correction, and keep long-exposure timing close at hand.

Free on the App Store iOS 18 or later

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Privacy-first metering

No photos captured or saved

What it does

Reads live exposure metadata from the iPhone camera, calculates a base shutter speed for your chosen aperture and film ISO, then applies film reciprocity correction where needed.

Built for film

Includes official datasheet-backed film profiles, plus clearly separated community and experimental tiers when manufacturers stop short.

Live Metering

Full-screen camera view

Meter with a live preview, expand to a full-screen view, and lock the exposure once framing looks right.

Reciprocity

Official data first

Uses manufacturer formulas and tables where available, with transparency when long-exposure guidance becomes community-derived or experimental.

Workflow

Metering ISO override

Override box speed when rating film differently, then carry the corrected time straight into the built-in bulb timer.

Film Library

Built-in film library

Browse built-in films with official, community, and experimental reciprocity data states where appropriate.

Screens

A closer look at the app

Current screenshots from the live App Store release.

ReciproMeter full-screen live meter showing a corrected 20-second exposure — Full-screen live metering with the corrected shutter time front and center.

ReciproMeter meter controls with film, ISO, aperture, and corrected exposure — Film, EI, aperture, base exposure, and reciprocity correction in one view.

ReciproMeter film library showing official, community, and experimental data tiers — Built-in films with official, community, and experimental data states.

ReciproMeter settings for appearance and optional reciprocity guidance — Appearance, data-source preferences, and privacy-forward settings.

Privacy

Camera metadata only

ReciproMeter asks for camera access so it can read live exposure metadata such as ISO, shutter speed, and aperture. It does not capture or upload your photos, and it does not require an account.

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Available now

Free on the App Store

ReciproMeter is available for iPhone on iOS 18 or later. It is free to download, requires no account and includes an ad at launch.

Get ReciproMeter

Film reciprocity, measured cleanly.