What PHOTARCH is, and why it exists
Photographs of objects in archives and collections cannot be compared. An object documented in one archive looks different from the same kind of object in another — different backgrounds, different lighting, different angles, different scales — and the scale, when there is one, sits on the picture rather than in the file. The result is a visual record that cannot be compared or measured.
This is not a minor inconvenience. It is a structural problem for research, conservation, and institutional memory.
PHOTARCH is a photographic method for objects in archives and collections, archaeological objects among them: a few principles that, followed, give uniform photographs that can be measured, again and again. Most objects in the archive are documented using the same controlled setup: one key light at half past ten and 45° above, a pure white ground, a ColorChecker read at capture, and the scale taken from a digital caliper on the object’s longest side, or from the board in the picture. Sides are defined — Front, Back, Top, Down, Left, Right and the four angles at the corners — so that the same object type is always documented the same way, regardless of who captures it or where.
The result is a visual dataset that behaves like data — not a gallery.
PHOTARCH is also a photo archive: an open, machine-readable database of photographs of the objects that organisations keep in their archives. Objects photographed by the PHOTARCH method can be published there by the organisations that hold them. Public access is free. Images and metadata can be referenced and cited by anyone; downloading is for members, and membership is free. The archive is built on persistent identifiers (NAAN 73195) so that references remain stable over time.
PHOTARCH is developed and operated by Milvus Productions AB in Ystad, Sweden. The method is developed by Daniel Lindskog (daniellindskog.com).
Every object in the PHOTARCH archive receives a persistent ARK identifier under NAAN 73195. These identifiers are designed to remain resolvable over the long term, independent of URL structure or platform changes.
photarch.com carries the method, the guides and the news. The open archive, accounts and organisations moved to archive.photarch.com, and the PHOTARCH app has its own page at app.photarch.com.
Every published picture and every download now carries a C2PA seal, countersigned by an independent timestamp authority, stating how the picture was made and what one pixel measures. The measurement travels as Image Scale Metadata, an open format PHOTARCH publishes and anyone may implement, and the published files carry their full record as XMP — so a picture can be read and measured wherever it ends up, without asking the archive. Objects enter the archive through the PHOTARCH app.
Objects publish as Linked Art (CIDOC-CRM) in JSON-LD, with material, technique and period mapped to the Getty Art & Architecture Thesaurus. LIDO and Europeana EDM export for organisations. Embargo dates that lift themselves on the day they name. A register of where the physical object is kept, alongside the photograph of it.
The PHOTARCH app pushes an object to the archive with its master, its measurements and its record; Sync keeps the two in step afterwards, and a picture replaced in the app is replaced here without losing its identifier. Pinned notes, attachments and 3D models travel with it. Deep zoom is cut from the master on arrival and served over IIIF.
Canvases arrange objects at true relative scale and can be embedded in another site, as can collections. Organisations define their own metadata themes and fields, and decide which of them are internal.
Google OAuth on login and signup. Researcher role with gated TIFF downloads. Public downloads capped at 1 MB JPEG. Newsletter opt-in at signup. Live object and institution counts on auth panel.
Archive opened without login gate. Public landing page for guests. Invite a colleague flow. Math captcha on all public forms. Navigation progress bar. Feedback form on account page. Angle image upload flow.
Interactive map with location picker. Timeline slider on archive. Data model v2: fragment support, external identifiers, IIIF readiness. Mobile pinch-to-zoom.
Archive grid with filter and freetext search. Object detail page with hero, metadata, scale bar, and gallery. Comparison viewer with true relative scale. Downloads with scale bar. Colour extraction and colour search. Dark mode. Admin edit page.
Initial build: Next.js + Supabase. Authentication and admin dashboard. Ingest pipeline with bounding box editor, crop step, and automatic colour extraction.
One version a year from now on, named for the year it serves, with updates every Monday. Print Layout lays chosen objects out for a printer or a PDF at one scale, at true size or one to a page. 3D models are turned, pinned with notes, stood on a canvas at their true size and joined from broken pieces. A Sony camera on the cable works in Capture, with live view, focus and exposure from the Mac. Loose markers without a board find and box the object between them. Alterations are recorded in the terms of CEN/TS 17135, condition is one scale, and Settings › Terminology chooses the field a collection is described in: Archaeology now, with more fields in development. Exports no longer carry serial numbers or GPS.
The Capture page takes several phones running PHOTARCH for iPhone at once: one is the active camera, the others photograph with their own shutter. Every object from a phone says who photographed it and on which phone, and an organisation’s library lets in only its own members. Capture draws the object’s box, size, rulers and guide lines over the viewfinder. Linked Art (CIDOC-CRM) as an export, with how the length and breadth were measured and by whom. Embargoes are counted in a time zone of your choosing.
Every import ends with a summary of what came in and what did not. XMP is read at import, from the file or a sidecar, and fills only empty fields. With a board in the picture, the board is read on every new photograph; a ruler or scale bar beside the object sets the scale by itself, even at an angle. Replace Original keeps the scale, crop, measurements and record. A close-up view beside the sides.
The first start asks where to keep the library. Exhibitions become a thirteenth collection-management procedure, with venue, case and dates. A missing original is shown by one warning instead of a red frame on every card. The question whether to look for new versions is asked in PHOTARCH’s own window.
A test board, Board Mini, prints from Settings at true size on A4 and is read in Measure. A licence bought on photarch.com or given to an account unlocks the app by itself, and a personal licence is active on one computer at a time.
The app says when there is a new version and can install it in the background once you have agreed; a check sends only the version you have, never anything from your library. Canvases with many objects move smoothly, each picture drawn at the size it is shown.
The PHOTARCH app, notarised by Apple, can be downloaded and bought: photograph, measure, validate and package a collection by the PHOTARCH method, with the scale written into every file it exports.
The app moved from Electron to a native macOS build: photograph, measure, validate, adjust and export, with every picture told plainly what it is fit for, what holds it back and what was not measured at all.
Milvus Productions AB · Org. nr 559505-9485 · info@photarch.com