LUMEN
Support & Documentation
A photo editor that answers to you
A full raw editor for Mac and iPhone — built natively in Swift, Metal-rendered, pixel-identical on both — that syncs through a WebDAV server you already own. No subscription. No cloud account. No proprietary catalog holding your work hostage.
Cloud editors move your originals onto someone else's disk, then rent them back to you by the gigabyte. Lumen syncs through plain WebDAV — a NAS, a Raspberry Pi, a rented box, or the Mac already on your desk, running as its own host. There is no Lumen server, and no Lumen account.
Your originals sit in dated folders as ordinary files. Delete the app tomorrow and nothing about them changes.
A subscription editor stops editing the day the payment does. Years of work becomes a folder you can look at but not develop.
Lumen has nothing to lapse. Every edit you make is a small, readable JSON file beside the photograph — so even the edits outlive the software, not just the pixels.
Mobile editors are usually a lesser cousin of the desktop — fewer tools, different results, a separate library.
The Mac and iPhone apps share the same Swift engine: the shader that renders a highlight recovery on one renders it on the other, checked byte-for-byte in the test suite.
Twelve panels, the same colors and the same order as the Mac's rail. Masking, retouch, curves, an eight-band mixer, three-way color grading — not a cut-down companion app, the same editor.
Camera, lens, exposure, ISO — the full EXIF record travels with the photograph, alongside ratings, pick and reject flags, and color labels, synced across every device in seconds.
Every tool is color-coded and in the same position on Mac and iPhone — after a week you reach for the green panel rather than reading the word "Masking."
Photographs and their edits travel separately. A raw file moves once; its edits are a few kilobytes of JSON that move constantly, so an adjustment made on the phone is on the desk before you are. A phone never needs your originals: it edits the same smart preview the Mac does, and asks for full resolution only when it genuinely needs it.
No NAS? The Mac can be the server — turn on Host mode and it runs a WebDAV server and preview worker itself. By default that's reachable only over Tailscale's encrypted private network, so your phone syncs exactly as it does at home, away from home too, with nothing exposed to the public internet and no ports to forward on your router.
Where things stand
Lumen is in active development. The Mac and iPhone apps are native Swift, built from source today — point either at a WebDAV server you already have, or let the Mac host for you.
Mac
Apple Silicon and Intel, macOS 14+. Library, Develop, export, the WebDAV host and the preview worker, all native.
iPhone, iPad
The same editor, not a companion app — including the iPhone Duo's wide layouts. Edits offline, syncs when it can.
Server
Any WebDAV host — Nextcloud, ownCloud, a NAS — or Host mode, built into the Mac app.