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Definition

What is photo archiving?

A short definition, the criteria that separate an archive from mere storage, and the method for building one.

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In short

Photo archiving means preserving images and their context so they remain identifiable, readable, and verifiable over time. It combines three elements: a structured description, a durable format, and proof of integrity checked periodically.

  • Archiving is not backing up: one freezes a documented state, the other duplicates a working state
  • An archive must carry its description, not only its files
  • Integrity is proven by cryptographic digest, not by opening a file
  • The 3-2-1 rule applies to archives themselves as well
  • A documented, open format is a precondition for long-term readability

The four criteria of an archive

A set of files only becomes an archive when these four conditions are met. At least one is almost always missing.

Identifiable
Every item carries a stable identifier that survives renames and reorganizations.
Describable
The context is written down somewhere: who, what, where, when, how, why.
Readable
The file format remains openable, and validation flags formats at risk.
Verifiable
A digest makes it possible to show the content has not changed since it entered the archive.

Archiving and backing up

The two words are often used interchangeably, which explains a large share of photographic data loss.

Purpose
A backup protects a working state. An archive preserves a reference state.
Duration
A backup is replaced each cycle. An archive is meant to last decades.
Content
A backup copies files. An archive preserves files and their description.
Verification
A backup is tested by restoring. An archive is checked by fixity audit.

The most common mistakes

None of them is dramatic, which is exactly what makes them expensive: they surface years later.

Relying on file names
A naming convention changes, and the context carried by names disappears with it.
Confusing sync with backup
Synchronization propagates deletions and corruption as faithfully as healthy data.
Never testing a restore
An untested backup chain has never demonstrated that it works.
Keeping only the files
Without description, a collection becomes a pile of images within one generation.

Step by step

Build a photographic archive

The method in five steps, independent of which tool you use.

  1. Gather and deduplicate

    Bring scattered sources together and discard duplicates by digest rather than by file name.

  2. Describe

    Document the context in a structured way and assign a persistent identifier to every item.

  3. Choose formats

    Prefer documented formats, and identify those whose future readability is uncertain.

  4. Seal and digest

    Freeze the set and compute a per-file digest, stored in a manifest.

  5. Copy and audit

    Apply the 3-2-1 rule, then periodically recheck digests and test a restore.

Questions

How is archive integrity verified?

Each archive includes a SHA-256 manifest and an Ed25519 signature. Scheduled fixity audits and format validation reveal drift or corruption.

How often should an archive be verified?

A quarterly fixity audit is enough to catch silent corruption before it propagates into backups. Scheduled audits remove the need to remember.

Which backup destinations are supported?

Amazon S3, Backblaze B2, Cloudflare R2, any S3-compatible storage, NAS, and local folders for a 3-2-1 strategy.

How does restore work?

Verified restore extracts a local or off-site archive after signature checks, with conflict options and overwrite safeguards.

What happens if I stop using Obscura Flow?

Your originals never left your disks, and metadata is written to XMP sidecars, a standard format other tools can read. Archives remain packages accompanied by their manifest: nothing depends on the application still being installed.

Continue

Photo archive software

How Obscura Flow implements this method.

Glossary

Fixity, manifest, sidecar, provenance: the terms defined.

Photo backup

The 3-2-1 rule in detail.

Decision

Build an archive that stays understandable.

Tell us about your context before the public opening of downloads and commercial offers.

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