The grainmag companion app

grainmag Companion App

Meter and place your tones without a signal. No account, no internet required — just you, the light, and the grain.

Gratis durante la beta · €9.99 pago único al lanzamiento · sin suscripción, sin cuenta, funciona completamente sin conexión.

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grainmag mapping a frame into Zones, region by region

New · on-device AI

A composition advisor that thinks on your phone

Shoot or pick a frame and grainmag reads the light — region by region — then talks through the composition and proposes where to place your key tones. A compact AI model runs entirely on the device: no cloud, no account, nothing ever uploaded.

Reads the frame in zones: It maps every part of the frame to its Zone — the same 0–X scale you meter by — so the advice is grounded in the tones actually in front of you.
Talks composition, not exposure math: Balance, leading lines, subject weight, where the tones fall. It speaks qualitatively and never invents an f-stop or EV — the numbers stay with the meter.
Suggestions you can tap to apply: Each tip is live: tap “Place top-center on Zone VI” and the metering engine recalculates the whole tonal range around that placement.
Runs fully offline — and private: The model lives on your phone. No connection, no account, no frame ever leaves the device. Works in a darkroom, a canyon, or aeroplane mode.

Available on supported Android devices (roughly 6 GB of RAM and up). iOS support is planned.

Composition

No notes — hang it in a museum

Qué hace

Six hand-built tools for working the Zone System in the field — plus the advisor above. Every one runs offline.

Zone Scale

An interactive reference of all 11 zones (0–X), from pure black to pure white. Slide the N+/N− development control to see how each zone shifts with expanded or contracted development.

Exposure Calculator

Dial in aperture, shutter speed, and ISO to see the resulting EV and the zone it maps to. Apply ±EV compensation and get the adjusted shutter speed instantly.

Zone Placement

Choose where your meter reads and where you want it in the final image. The app calculates the stop offset and shows how the whole tonal range shifts.

Reciprocity Correction

Corrected long-exposure times for 11 film stocks — Tri-X, T-Max, HP5 Plus, FP4 Plus, Delta, Acros II, Fomapan and more — with a quick-reference table.

Filter Compensation

Select contrast filters, ND filters, or a polarizer and see the total stop adjustment applied to your base shutter speed.

Live Zone Overlay

Shoot or pick a photo and the app maps every region to its zone — tap any cell to read its tone, then dial EV and development to watch the whole scene shift.

Solicitar acceso beta

grainmag Companion App está en fase de prueba cerrada en Google Play. Déjanos tus datos y te añadiremos a la lista de testers; luego te enviaremos el enlace de inscripción por correo. Usa el mismo email que tienes en tu cuenta de Google Play.

1. Nos envías tus datos arriba.
2. Añadimos tu email a la lista de prueba cerrada en Google Play.
3. Te enviamos el enlace de inscripción por correo — pulsa sobre él, instala y ya estás dentro.