Data Recovery Case File · Cameras, Drones & Cards · Sustained Write Is the Test

High Frame Rate Is Where Cards Are Found Out

Her enquiry pins the failure to a demanding moment. Recording at 100 frames per second when "the camera suddenly showed up with an error message saying something like 'error writing on card'. Now I cannot use the card or access any of the media either through the camera or when I put it into a laptop. I was shooting for 2 hours before this happened and really need that foo"tage. High frame rate video is the heaviest sustained write a card will ever be asked for — and a card that cannot keep up does not slow down gracefully, it stops.

The decode: why the write failed, and what it left behind

What high frame rate actually demands: a continuous, uninterrupted stream of data at a fixed rate for as long as the take lasts. Recording at 100 frames per second produces several times the data of normal recording, and the camera has only a small buffer — so if the card cannot absorb the stream continuously, the buffer fills and the camera has no choice but to stop and report an error. There is no option to record more slowly.

Why a card that used to cope can stop coping: flash memory slows as it ages. Blocks accumulate wear, the controller does more work managing them, and sustained write performance degrades well before anything else shows a symptom. A card that handled the same footage a year ago may no longer sustain the rate — and nothing tells you until a take fails. Two hours of shooting also means the card was working hard and warm throughout, and heat reduces performance further.

What the interruption left: the important part, and it is hopeful. When a recording stops abruptly, the video data already written is on the card — but the container's index, which describes where each part of the recording lives and how long it runs, is normally written when the file is closed. An interrupted recording therefore leaves a file with content and no index, plus filesystem structures that were mid-update. The footage exists; nothing knows how to present it.

Why the card is now unreadable everywhere: the filesystem structures were being updated at the moment of failure and are inconsistent, so neither the camera nor the laptop can interpret the volume. Consistency across both devices confirms the card rather than either host.

Why camera footage recovers well: the containers are large, written contiguously, and carry recognisable headers — so they can be identified and extracted regardless of the filesystem. Where the index was never written, the stream can frequently be rebuilt into a playable file, which is a specific technique rather than a general carve.

What must not happen: no formatting, in the camera or on the computer, and no camera-offered repair. Both will be proposed.

The practical note for future shoots: for high frame rate work the card's sustained write specification is the number that matters, not its peak or its capacity — and cards used hard should be retired on a schedule rather than kept until they fail mid-take.

On the bench

No format or camera repair was permitted, both devices offering one. The card was imaged write-blocked behind the DeepSpar USB Stabilizer 10Gb, structures reconstructed on the image from their surviving copies, and format-aware carving for camera containers run alongside — an interrupted recording leaving stream data written with the container index never completed, so the stream is rebuilt into a playable file rather than merely extracted. Footage was validated by playback and reported by duration against the session length.

The outcome

The card imaged write-blocked, structures rebuilt and the interrupted recording reconstructed into playable form, validated against the session duration. Free assessment, one fixed written figure including VAT; where a chip has to be removed, 50% of parts and labour is payable upfront with the balance only on success — otherwise no recovery, no fee. The decode: high frame rate demands a continuous write the camera cannot slow down, so a card that stops sustaining it forces an error. Your footage is on the card — what is missing is the container index, which is written when a file closes, and filesystem structures that were mid-update. Refuse every format.

Our case files are drawn from genuine enquiries received by our laboratory over the past ten years, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery procedure our engineers apply to that fault, using the equipment listed.