Eltham Archive Removes Hundreds of Duplicate Photos From Digitization Project

Eltham's community archive holds thousands of photographs spanning more than a century of local life, the old cinema on Well Hall Road, the original market stalls at Eltham High Street, the construction of the Progress Estate in the 1910s. But for the past three years, volunteers and staff at the Eltham Local History Society have been quietly working through a problem that crept into the collection almost unnoticed: a significant portion of the digital catalogue is made up of duplicate images, some appearing four or five times under different file names and reference numbers.

The issue matters now because Greenwich Council's Heritage and Libraries team is preparing to migrate the entire borough-wide digital archive onto a new public-access platform, with a target launch date of October 2026. If duplicates are not resolved before migration, the new system risks inheriting the same bloated, confusing catalogue, making it harder for residents, researchers and schools to use the collection.

How the Duplicates Got In

The roots of the problem go back to a digitisation push that began around 2018, when the Eltham Local History Society partnered with the Well Hall Community Centre to scan physical prints, glass plates and newspaper cuttings donated by local families. The project used two separate scanning stations, each running different file-naming conventions. Batches uploaded from volunteer sessions were not always cross-checked against what was already in the system, and when a second wave of donations arrived in 2021, including a large collection from a family in Mottingham, many images that had been scanned previously were scanned again without anyone realising.

The 2021 intake alone added an estimated 340 new entries to the digital index, but staff reviewing the collection in early 2024 found that roughly 90 of those were near-identical copies of images already catalogued. The problem was compounded when the archive briefly used a third-party cloud storage service in 2022, which automatically generated backup copies during a system migration, some of which were imported back into the main catalogue by mistake.

Greenwich's Heritage Unit became formally aware of the scale of the duplication in March 2025, following an internal audit. The audit, carried out ahead of the planned platform upgrade, flagged that the Eltham sub-collection contained the highest concentration of duplicate entries of any neighbourhood archive in the borough.

Untangling the Archive

Since late 2025, a small working group, drawn from the Eltham Local History Society, staff from Eltham Library on Eltham High Street, and two volunteers from the Southeast London Photography Collective, has been systematically working through the flagged entries. The process involves comparing metadata, original scan dates and image dimensions to determine which version of a duplicated photograph should be treated as the primary record and which should be deleted or merged.

The work is slow. By June 2026, the group had reviewed around 600 of the estimated 850 flagged entries, according to a progress update circulated to Friends of Eltham Library members. Each review session at Eltham Library typically covers 40 to 60 images in a two-hour block. Some decisions are straightforward, a higher-resolution scan clearly supersedes a blurry earlier version. Others require cross-referencing with paper donor records kept in filing cabinets at the Well Hall Community Centre, which adds days to the process.

The cost of the wider platform migration is being met through a £120,000 grant awarded to Greenwich Council in 2024 under the Arts Council England Local Culture Fund. A portion of that budget covers the deduplication work, though the Local History Society has also relied heavily on unpaid volunteer hours.

For residents who use the archive, whether tracing family history, researching planning applications, or sourcing images for community events, the practical advice for now is straightforward: if you find two versions of the same image in the existing online catalogue, use the contact form on the Greenwich Heritage Centre website to flag it. The working group is incorporating those reports into their review queue. The October launch date has not been formally changed, but those involved in the project acknowledge the timeline is tight.