One stop grading tool for iPhone ProRes + AppleLog footage. This is a personal use tool, not a product.
Why? iPhone Pros from the 15th generation on shoot in log, which retains enough depth to edit professionally — dynamic range, shadow detail and 10-bit colour, good enough to sit alongside footage from professional cinema cameras. Log holds real highlight headroom and none of the HDR tone mapping or sharpening a normal phone capture bakes in.
Getting that out of it requires an understanding of colour spaces, LUTs and exposure, and usually professional software. This tool gets about as much image quality out of iPhone footage as the format actually holds, without opening an NLE. Pick a look (Neutral, or a film stock: Portra 160, Portra 800, Super 8) and the footage comes out finished.
Why not an existing app? Log files are ordinary video, so any app opens them, but they look flat and grey until they are converted and graded. The free tool that does that properly is DaVinci Resolve, a full professional suite. Final Cut Pro converts Apple Log, but it is a paid editor and the look is still yours to build. Editors that accept LUTs expect you to bring one. None of them is quick: footage in, a good look, a file out.
./app/make-app.sh # builds dist/LogGrade.appBuild it optimised: the preview grades every frame with the whole chain, and a debug build is
unusable. H.264 exports render on the GPU where they can, about 1.5 times faster than the ffmpeg
engine they are tested against, which renders everything else. → USAGE.md for the controls and the CLI underneath.
Most grading tools approximate while you drag and render when you stop. This one grades every picture, dragged or settled, with the whole chain, and tests hold it to the exported render. There is no preview button and no slower "exact" render replacing it.
→ adr/0009
Settings for Final Cut Camera 2.4. The tool meters exposure and white balance once per clip, so it can correct a clip that is off, but not one that drifts while recording: lock everything.
| setting | choice |
|---|---|
| Format | Apple Log, ProRes |
| Frame rate | 25 fps where mains power is 50 Hz, otherwise 24 |
| Exposure | Manual |
| Shutter | Angle, 180°. At 24 fps under 50 Hz lights, 172.8° to stop flicker |
| ISO | the lowest that exposes the shot; a variable ND in daylight, not a faster shutter |
| Exposure target | false colour on, faces at or just above mid-grey, nothing that matters clipped. Log shadows are noisy, so err bright |
| White balance | manual, set to the light |
| Focus | manual or locked |
| Timecode | time of day, so a second camera or sound recorder lines up |
macOS 13 or later. Nothing to download: the app renders Apple Log with its own conversion. It builds as one universal bundle for Intel and Apple silicon, developed on Intel and not yet verified on Apple silicon.
PolyForm Noncommercial 1.0.0. Run it, change it, share it, keep the attribution.
Commercial use needs permission. The film stocks in luts/film/ are baked from spektrafilm and
keep its terms (luts/film/SPEKTRAFILM_LICENSE.txt).