Cameras and cards · partial corruption · ADR-2025-3667
The Preview Opens. The Photograph Does Not.
He could see the pictures and could not have them. His raw files appear to be corrupt
, he wrote, though he could still see the thumbnail images In preview
— and when one was opened properly it came up white, with coloured lines across them
. Every frame behaved the same way. He had the CompactFlash card the photographs were made on, and he had a set of copies of the same files on a hard drive, and he wanted to know which of the two was worth working on.
Same story on yours? Tell us what it does — the look is free.
0203 0868633
What failed, and why.
A RAW file is two pictures in one wrapper. There is a small preview, written so a camera can put something on its screen at once, and there is the full-resolution data, which is very much larger and sits elsewhere in the file. A viewer will happily show you the first and fail on the second, and that is exactly the symptom he described. So the corruption is not general. It has reached the large part and spared the small one, which narrows the possibilities to two: either the full data was never completely written, or it is present and the card is handing back something wrong when asked to read it. Those two have different outcomes, and telling them apart is the whole of the diagnosis.
What the bench did with it.
The order of the job →| Equipment used | Its work on this job | The reason for it |
|---|---|---|
| PC-3000 Flash | One controlled read of the card made in full before anything was examined | Reads flash directly off the chips, going round the controller, with a maker-ID library kept current here |
| R-Studio Technician | The two sources compared file by file, and the cleaner of the pair used each time | Puts an array back together from the images, and reads nearly every file system |
| UFS Explorer Professional Recovery | The card's own file system opened off the copy, and each frame recovered from it drawn on screen | Opens APFS, ReFS, XFS, ZFS and Btrfs when other software will not |
What the bench did with it.
Copy both sources before reading either
Two sources arrived and both were copied before either was examined: the card behind a write blocker on a controlled reader, and the drive holding his copies. Everything after that ran against those copies. Having two versions of the same photograph is genuinely useful, but only if neither of them can be altered while the comparison is going on.
Find where in the file the damage sits
Each file was opened at byte level rather than in a viewer, and the boundary between the intact preview and the damaged full-resolution data was located within it. That is what separates a frame which was never finished from a frame which is complete on the card and coming back wrong. The first is limited by what exists. The second is a reading problem, and reading problems can be worked at.
Then read the card again
Where the fault looked like a read rather than a write, the card was gone over again at a lower level, and cleaner full-resolution data came back for a number of the frames. Where the data had never been written completely, no amount of re-reading adds any, and those frames are what they are. He was told which of his files fell into which group.
What went home.
The photographs came back at the best resolution each file could support, which for most is the full frame and for the rest the preview and no more. Nothing was described as recovered until it had been opened and looked at. A card or a memory stick carries the published figure of £250 + VAT, and the examination that settles which fault you have costs nothing.
Begin here if yours is doing the same thing.
More jobs where files would not show and volumes would not read.
Yours doing something similar? Power it down first.
Prices are published and fixed. Memory cards and USB sticks are priced at £250 + VAT. A drive on its own comes to £300 + VAT. Anything holding a second disk, whether RAID, NAS or a server, opens at £500 + VAT. The first look costs nothing, and the figure that follows is fixed and in writing before a penny is charged. Switch it off and post it in. Most jobs carry no fee where no files return.