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.

Free during the beta · €9.99 one-time at launch · no subscription, no account, works fully offline.

What it does

Zone Scale screen

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 screen

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 screen

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 screen

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 screen

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 screen

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.

Request beta access

grainmag Companion App is in Google Play closed testing. Leave your details and we'll add you to the tester list, then email you the opt-in link. Use the same email as your Google Play account.

By requesting access you agree that we may store your name and email to add you to the Google Play closed test and send you the opt-in link. We won't use it for anything else. See our Privacy Policy.

  1. 1. You send your details above.
  2. 2. We add your email to the closed-testing list on Google Play.
  3. 3. We email you the opt-in link — tap it, install, and you're in.