metalign — a field logbook for film photography

pronounced meta-align

What isn't recorded on film.

A field logbook for film photography. You log each frame as you shoot, and metalign writes the log into your scans.

A film scan comes back from the lab without metadata: no camera model, no timestamp, no exposure settings, no location. None of that is recorded on the film. So somebody has to write it down.
When the roll comes back, it goes in as real metadata, the way a digital camera stores it.

metalign, coming soon Read the handbook

For iPhone, iPad and Apple Watch · iOS and iPadOS 17 or later, watchOS 10 or later · no account, no tracking

One scan of a real roll, frame 18, R1-01269-0017.JPG: from the lab and with metalign. The picture is reduced; the larger copy carries the right column as metadata.
Frame 18: the Schlern above the Seiser Alm on a day of heavy cumulus. A weathered wooden fence runs down across the alpine grass in the foreground, and jagged Dolomite peaks stand along the horizon behind it.
Field As delivered After metalign
Camera—Leica M6
Captured—Sep 2, 2026 11:35
Exposure—1/1000 · f/8 · ISO 400
Lens—Nokton Vintage Line 35mm f/1.5 Aspherical
Film—Kodak Portra 400
Location—46.5077° N, 11.5749° E

At the shutter

Load a roll

Which film, which format, and the ISO you're rating it at. Or scan the barcode on the box: say which film it is the first time. After that, metalign fills it in. Your other film is in the app too: what's in the fridge or freezer and what expires when. Plus where every roll stands, from Unused to Scanned.

The New roll form, with a barcode button in the top bar beside the tick that adds the roll. At the top, Stock Kodak Portra 400 and Add a film stock…; under Camera, Load into a camera now switched on, Body Leica M6 and Lens Voigtländer Nokton Vintage Line 35mm f/1.5 Aspherical, with a note that it is kept as this camera’s usual lens; under Roll, Number #2, Rolls: 1, Name with Optional label, Frames: 36 and an empty Expires row, with Metered at cut off by the bottom edge of the screen.

New roll — the film first, then the camera it goes into.

  1. The film, or the barcode on its box.
  2. Load it straight into a camera from here, with the lens that's mounted now.
  3. The roll's number, given before it goes in.

Log each frame

Two dials and one tap. Time and place come along by themselves, the dials stay where you left them, and a run at the same settings costs a tap a frame. Camera at your eye, phone in a pocket? With Show as Live Activity, the loaded roll sits on the lock screen with a button for the next frame. With a Log Frame control you log one from the lock screen, the Action button or Control Centre. On Apple Watch too, you log frames on the same roll. metalign guesses no exposure when you log a frame without the dials. That is on purpose: better no data than a guess.

A loaded roll on the phone: #1 Leica M6, Loaded, a C-41 badge before Kodak Portra 400, Seiser Alm / Regensburg and 13 / 36. The frame list shows frame 13 at 1/1000 and f/9.5 with the note Schlern summit cross, frame 12 at 1/1000 and f/9.5, and frame 11 at 1/1000 and f/13 passing under the capture bar. The bar carries the lens 35mm f/1.5, No filter and a flash bolt, a shutter dial with 1/1000 chosen, an aperture dial with f/9.5, and a round camera button beside a Log frame 14 button.

Frame 14 — 1/1000, f/9.5 and the place, one tap.

  1. Every frame already logged, newest first, with the time it was taken.
  2. Two dials, held between frames. Set them once and they stay.
  3. With one tap, you log the next frame, with its time and place.

When the roll comes back

Check the pairing

Weeks later the lab sends back scans named after a job number. metalign lines them up against the log by position, the first frame to the first scan and so on. A frame you logged nothing for gets its place too. You see the pairing before anything is written. So you notice here whether a roll slipped by one frame, not in your scan folder.

The Scan pairing screen, reading 38 scans · 40 frames, with Arrange and Scans beside the count. Numbered rows pair frames with scan files: frame −1, No exposure recorded, holds a Placeholder; frame 0, at 1/1000 and f/8 with the note Into the sun, still on the leader, sits over R1-01269-0000.JPG; frames 1, 2 and 3 sit over R1-01269-0000_0001.JPG, R1-01269-0001.JPG and R1-01269-0002.JPG, and frame 4 runs under the tab bar at the foot of the screen.

38 scans against 40 frames, laid out before a single byte is written.

  1. A placeholder where the lab scanned nothing, here the press on the leader. It keeps every scan below on its own frame.
  2. A note written at the shutter, beside the scan it belongs to.
  3. A frame paired with the file the lab returned.

Write onto the scans

With one tap, you write the log into the scans: shutter, aperture, lens, film, the time each frame was taken in the time zone it was taken in, and where. All of it is in the files themselves, as real EXIF and XMP, and it shows up in photo apps too. The picture is left alone: the pixels are not changed and not recompressed. Then the app reads every file back and checks it. Scans from Files are copied into a new album in Photos or a new folder in Files. The lab's delivery stays as it came unless you choose to overwrite it. A photo from Photos gets the log as an edit, and Revert there brings the original back. The written roll stays in the app as a contact sheet.

The Rolls tab showing a written roll as a contact sheet, under a search field reading Film, gear, place or note. A header reads Seiser Alm / Regensburg, Kodak Portra 400, Sep 30, 2026. Below it, colour scans of Dolomite peaks and alpine meadows, laid out three across, each carrying its frame number in the corner from 0 to 11, and a fifth row running under the tab bar.

The roll comes back into the app as a contact sheet.

  1. Which roll this is, and the film it was shot on.
  2. Each written scan, under the number of the frame it was paired with.

At the shutter, without the phone in your hand

Most of a roll gets shot with your phone in a pocket, and it can stay there. At the top of a loaded roll, tap Show as Live Activity. The roll then sits on the lock screen with a button for the next frame. You need to unlock the iPhone for that first. With a Log Frame control on the lock screen, you log a frame without unlocking the iPhone. The same control goes on the Action button or in Control Centre, with no shortcut to build. And Siri logs a frame by voice, with a note if you want one.

Apple Watch shows all cameras with film in them, a turn of the Digital Crown apart. It works with your iPhone out of range. The frame is saved on Apple Watch until the iPhone is back in range. Then it goes onto the roll that was loaded when you pressed, at the time you pressed, even if you have loaded another roll since. Apple Watch measures the position itself, since it is usually right there at the camera.

metalign guesses no exposure for you on any of them. When you log a frame without the dials, metalign records the time, the place and the gear. Shutter and aperture stay blank unless you give them. On Apple Watch, the dials have a page of their own, so a frame logged from your wrist can carry an exposure too.

A loaded roll on the lock screen as a Live Activity. It reads Leica M6, then #1 · Kodak Portra 400 · Seiser Alm / Re…, a progress bar, and 13 of 36 · 1/1000 f/9.5 · 09/02, 10:42. To its right a filled button carries the metalign mark above the words Log 14.
The lock screen: the count, and the next frame.
The roll on an Apple Watch: Leica M6, Kodak Portra 400, 13 / 36, and the last frame's time, 09/02, 10:42. A full-width Log frame 14 button fills the lower half, with an open padlock in the top corner and a tick in the other.
One camera at a time, the Digital Crown to the next, and the padlock that stops a stray swipe.
The next page on the watch, its dials. Leica M6 at the top with a flash bolt in the corner, then 1/1000 outlined in green beside f/9.5, a Lens row reading 35mm f/1.5, and the same full-width Log frame 14 button underneath.
A page of their own for the dials, so a wrist frame can carry an exposure too.

metalign compared to other logbooks

Logging frames is not a new idea, and there are honest apps in the field. This is where metalign differs from most of them.

What The usual logbook metalign
Logging a frame Open the app; each setting gets a picker that opens when you tap it. The dials sit in the capture bar, holding where you left them. With one tap, you log the frame, time and place included.
With the phone in a pocket Mostly, the app is the only way in. With Show as Live Activity, the roll sits on the lock screen with a button for the next frame. With a Log Frame control you log one there without unlocking, and from the Action button or Control Centre, with no shortcut to build. Siri logs one by voice, with a note if you want one.
Apple Watch Few have one. Every loaded body a turn of the Digital Crown apart, with its dials on a page of their own. The iPhone can stay out of reach: the frame is saved on Apple Watch and goes onto the roll later, at the time you pressed. Apple Watch measures the position itself.
What gets logged for a frame The exposure, the gear, a time and a place, sometimes a note. Those, plus the filter with its cost stated in stops, flash, a title and a caption, how the frame was logged, and the light it was made in: golden hour, blue hour, the sun's height and direction.
When the scans come back The log is handed to a computer, as a CSV, an ExifTool script or a desktop app, and the metadata is written there. The roll is finished on the phone: pair, check, write. A lab's JPEG scans are saved to Files or Photos with the log as real metadata.
Matching scans to frames Done once, by eye, and taken on trust. Laid out to check: blank frames and missing scans each get their own mark, and each is fixed right there in the table. metalign warns about a wind-on shot at the head of the roll, and with a long press you see the scan.
Writing onto the scans Assumed to have worked. Pixels are not changed and not re-encoded. The app adds the log to what the file already carried, then reads every file back. One that lost its capture date is not delivered.
The film in the fridge A list of rolls. An inventory: storage, fridge and freezer, expiry as the box prints it, and barcodes learned from your own boxes. Part-shot rolls are marked as such.
The gear Names you type in yourself. Lenses and films picked from a built-in catalogue, a lens with its real ring clicks. A body you describe once, with its shutter dial's real speeds. If the camera's frame counter starts below 1, so does metalign's.

Shoot the next roll logged. metalign is coming soon for iPhone, iPad and Apple Watch; until it lands, the handbook has the whole workflow.