metalign — a field logbook for film photography

pronounced meta-align

Everything a frame should have carried.

A film scan comes back from the lab knowing nothing about itself: which camera, when, what settings, where. Film doesn't record any of that, so somebody has to write it down.
With metalign that happens as you go: log each frame as you shoot, and when the roll comes back, the log is written into your scans as real metadata, the kind a digital camera would have put there itself.

metalign, coming soon Read the handbook

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

One scan of a demo roll, MountRobson-07.jpg — as the lab returns it, and after its log is written.
Field As delivered After metalign
Camera—Leica M6
Captured—Aug 8, 2026 12:31
Exposure—1/250 · f/8 · ISO 100
Lens—35mm f/2
Film—Adox CHS 100 II
Location—53.1094° N, 119.1564° W

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 and the film fills itself in. Between rolls your film lives here too: fridge, freezer, expiry date, and where each roll stands, from Unused to Scanned.

The New roll form, with a Scan the film box button in the top bar beside Add. Stock Adox CHS 100 II; under Roll, Number #2, Rolls: 1, Frames 36, an Expires row and Metered at ISO 100; under Camera, Load into a camera now is switched on, at the bottom edge of the screen.

New roll — the film at the top, the camera at the bottom.

  1. The film, or the barcode on its box.
  2. Metered at — the speed you rate the roll at. It follows the box unless you're pushing.
  3. Load it straight into a camera from here.

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? The loaded roll sits on the lock screen with a button that logs the next frame, the same Log Frame control goes on the Action button and in Control Centre, and Apple Watch logs onto the same roll. A frame logged with no dials in front of you records no exposure. That is on purpose: better no data than a guess.

A loaded roll on the phone. The frame list shows frame 6 at 1/250 and f/8, frame 5 at 1/125 and f/5.6 flagged, and frame 4 with no exposure recorded. Across the foot sits the capture bar: the lens 35mm f/2, No filter, a shutter dial with 1/250 chosen, an aperture dial with f/8, and a full-width Log frame 7 button.

Frame 7 — 1/250, f/8 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. One tap logs the next frame, with the time and the 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 — frame 1 to the first scan, a blank frame holding its place — and lays the pairing out to check before anything is written. A roll that slipped by one frame shows up here, not in your scan folder.

The Write onto scans screen, reading 4 scans · 6 frames. Numbered rows pair frames with scan files: frames 1 to 4 carry MountRobson-01 to -04.jpg, frames 2 and 3 read Blank frame beside a solid square mark, and frame 5 reads No scan beside a dash. Frame 6 runs under the tab bar at the foot of the screen.

Four scans against six frames, laid out before a single byte is written.

  1. A frame paired with the file the lab returned.
  2. A blank frame — a negative nobody logged on. It usually does have a scan, so this pairing is most often right; the log just can't confirm it.
  3. A frame with no scan at all — the roll is longer than the delivery.

Write onto the scans

One tap writes the roll: shutter, aperture, lens, film, the time each frame was taken in the time zone it was taken in, and where. All of it goes into the files themselves, as real EXIF and XMP, the metadata photo apps read. The picture is left alone: the pixels are copied as they are, never recompressed, and every file is read back and checked before you get it. Scans from Files are replaced where they sit; a photo written back onto itself keeps its Revert. The written roll stays in the app as a contact sheet.

The Rolls tab showing a written roll as a contact sheet. A header reads Mount Robson, Adox CHS 100 II. Below it, six monochrome scans of a ridge above a lake, laid out three across, each carrying its frame number in the corner from 1 to 6.

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. The loaded roll sits on the lock screen with a button that logs the next frame without unlocking. The same Log Frame control goes on the Action button or in Control Centre, without building a shortcut first, and Siri logs a frame by voice, with a note if you have something to say.

Apple Watch keeps a page for each camera with film in it, and it works with your phone out of range: the press is saved on the watch and lands on the roll at the time you pressed, not the time the phone caught up. It takes its own location as you press, since it is usually right there at the camera.

None of these guess an exposure for you. Log a frame with no dials in front of you and it records the time, the place and the gear, and leaves shutter and aperture blank. One more swipe on the watch brings up its dials, 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 · Adox CHS 100 II · Mount Robson, a progress bar, and 6 of 36 · 1/250 f/8 · 08/08, 12:25. To its right a filled button carries the metalign mark above the words Log 7.
The lock screen: the count, and the next frame.
The roll on an Apple Watch: Leica M6, Adox CHS 100 II, 6 / 36, and the last frame's time, 08/08, 12:25. A full-width Log frame 7 button fills the lower half, with an open padlock in the top corner and a tick in the other.
A page per loaded body, and the padlock that stops a stray swipe.
The next page on the watch, its dials. Leica M6 at the top, then 1/250 outlined in green beside f/8, a Lens row reading 35mm f/2, and the same full-width Log frame 7 button underneath.
One swipe on: 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; one tap logs the frame, time and place included.
With the phone in a pocket Mostly, the app is the only way in. The loaded roll sits on the lock screen with a button for the next frame; the Action button and Control Centre log one without building a shortcut first; Siri logs one by voice, with a note if you have something to say.
Apple Watch Few have one. A page per loaded body with its dials one swipe away, and the phone can stay out of reach: a press is kept on the watch and lands on the roll at the time you pressed, with the location fix the watch itself took.
The record a frame keeps 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 go back into Files or Photos carrying 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; a wind-on shot at the head of the roll raises a warning, and a long press shows the scan.
Writing onto the scans Assumed to have worked. Pixels are copied, never re-encoded; the log merges onto what the file already carried; every file is read back before delivery, and 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, barcodes learned from your own boxes, and a part-shot roll that says so.
The gear Names you type in yourself. Picked from a built-in catalogue: a body's real shutter speeds, a lens's real ring clicks, a frame counter that starts below 1 when the camera's does.

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