Who This Is For
You commission photography whose images may later need to hold up: a site condition before works start, samples in a study headed for litigation, damage for a claim, an inspection an expert will rely on. The photographer is competent and the images are good. What is usually missing is one paragraph in the engagement letter saying what records to keep, because nobody thought to write it down before the first shoot.
This page is that paragraph, with the reasons behind each line. It is written so that a law firm or a consultancy can paste it into the engagement and a working photographer can meet it without buying new equipment. Lumethic builds software and does not give legal advice; what the records are worth in a particular forum is a question for the people running the matter.
The Requirements
- Scope in writing. State what is to be photographed, for what purpose, and who will receive the images, before the first shoot. A photographer who knows the images may be relied upon works differently.
- RAW plus JPEG, camera clock set. Every frame is captured in the camera's RAW format alongside any JPEG, and the camera's date, time and time zone are set against a reliable reference before each shoot day. Inconsistent clocks are the easiest cross-examination target there is; the camera setup checklist covers the rest.
- A content-binding hash list at the first backup. When the card is first copied, a list of cryptographic hashes of every file is written by the offload tool (C4 in OffShoot, Silverstack or ShotPut Pro) or by a hashdeep run against the untouched copy (SHA-256) before any catalog software touches the files. xxHash, the speed checksum most tools use by default, does not bind file contents and is not sufficient. The checksum settings guide shows the setting in each tool.
- An independently dated receipt for every card, on the day it is backed up. The hash list is anchored with an independent timestamp authority, so that its existence at that time does not rest on the photographer's own records. One receipt covers the whole card. Nothing covers the card before the backup, so the backup happens on the shoot day.
- Originals kept, unmodified. The RAW files and the first backup are kept as written, together with the hash lists and receipts. Editing happens on copies. Original cards are retained until the matter is closed where practicable.
- Exhibits verified against their originals. Each image that is delivered, becomes an exhibit, or goes into a report is checked as a RAW and JPEG pair, and the report states what was checked, the scores, and the methodology version. Only the delivered images need this; the receipt already covers the rest of the card.
- Records delivered with the images. Receipts, verification reports and the hash lists are delivered to the commissioning party with the images, as files and as share links that open without an account, so that the other side can check them too.
- No deletion once a dispute is foreseeable. Once a claim or a proceeding is in prospect, nothing in the record set is deleted or altered without instruction from counsel.
Wording for the Engagement Letter
The Photographer will capture all images in RAW format with a correctly set camera clock; will, at the first backup of each memory card and before any cataloguing software processes the files, produce a hash list of every file using a content-binding checksum (C4 or SHA-256); will have each hash list anchored with an independent timestamp authority on the day of the backup and retain the resulting receipt; will retain all RAW originals and first backups unmodified; will verify each delivered image against its RAW original and deliver the verification report; and will deliver all receipts, reports and hash lists to the Client with the images. Once a claim or proceeding is in prospect, the Photographer will not delete or alter any part of the record set without the Client's written instruction.
That paragraph asks for nothing exotic. The hash list is a setting in the offload tool or one command line. The receipt takes two minutes per card, and verification applies to a handful to a few dozen exhibits per matter rather than to every frame. The legal evidence workflow shows how the pieces fit on a ten-day field job.
What This Sheet Does Not Do
It does not make a photograph admissible. Photographs come into a case through the person who vouches for them, and what a court makes of the records is decided by the rules of the forum and the people running the matter. The records answer a question testimony cannot settle on its own: when the file could last have been changed. A receipt proves that the files on a card existed no later than an independent anchor time and, with a content-binding checksum, have not changed since. A verification report states that a delivered image is consistent with its camera RAW within stated thresholds. Neither says anything about whether the scene was what it appeared to be, and neither is an examiner's opinion. What a Lumethic record contains sets out the claims, the limits, and how to check them.
Requirements FAQ
Does the photographer need special software? An offload tool that writes hash manifests helps but is not required. A free command-line tool, hashdeep, produces a SHA-256 list from any folder, and Lumethic accepts that list directly.
Do we need Lumethic accounts to receive the records? No. Receipts and reports are shared through links that open without an account, and every receipt can be checked on a public page or with standard cryptographic tools without trusting Lumethic.
What about photographs taken on a phone? The same requirements apply where the phone can meet them. Most phones cannot produce a RAW original or a first-backup hash list in the same way, which is why the requirements ask for a camera where the images may matter.
How long should the records be kept? At least for the life of the matter plus any appeal or limitation period, which counsel can state. Receipts verify with standard tools for as long as the timestamp authority's certificate can be validated; keep the downloaded receipt, the hash list and the originals together.
Can the other side check the records? Yes. Anyone holding a receipt can re-verify it, and a verification report states its methodology and scores so it can be examined rather than taken on faith.
