Metadata
Two risks to weigh
Writing into the file keeps everything together: the description can’t be separated from the image. But every write modifies an original, and a failed write on an irreplaceable RAW is a permanent loss.
Writing alongside, in an .xmp sidecar, never touches the original. But the description becomes a second file, which can be lost, missed in a copy, or orphaned after a rename.
There’s no universal answer. There’s an answer per format.
The answer by format
Proprietary RAW (NEF, CR3, ARW, RAF…): sidecar. These are closed, publicly undocumented formats their makers don’t guarantee for rewriting. A third-party tool rewriting a NEF header takes a risk nothing justifies. It’s also what Lightroom does by default, for the same reason.
DNG: into the file. The format is open, documented, and designed to carry its metadata. A sidecar adds nothing but orphan risk.
TIFF and JPEG: into the file. Stable formats, writing well handled by every tool. The simplest case.
Derivatives and deliverables: into the file, always. An image leaving your studio must carry its author, rights, and caption within itself. A sidecar will never follow a JPEG sent by email.
The strategy that covers both risks
Serious collections don’t choose: they duplicate. Three locations for the same information, with different roles.
- The catalog is the working source. That’s where you enter, correct, and search.
- The file or its sidecar is the copy that travels. It guarantees the information survives losing the catalog.
- A plain inventory export — CSV or XML — is the copy that survives the software.
The consistency rule: the catalog writes to the other two, never the reverse without explicit arbitration. Otherwise two truths diverge and you no longer know which to believe.
The non-negotiable rule
Whatever you choose, insist on merging rather than overwriting. A sidecar or XMP block may hold fields written by another application. A tool that rewrites the whole file destroys them without warning — the most common cause of metadata loss when changing tools.
In practice
- Sidecar for proprietary RAW, internal writing for DNG, TIFF, JPEG.
- Always into the file for anything leaving your studio.
- Verify your tool merges rather than overwrites, before adopting it.
- Keep a plain inventory export as a third copy.
- Never rename an image without its sidecar in the same action.
Obscura Flow doesn’t alter originals, merges XMP sidecars while preserving blocks it doesn’t manage, and exports the full inventory as flat CSV — the three copies stay consistent without one overwriting another.