You get home from the trip, put the card in the reader, and the folder is empty. Or the camera says the card needs formatting. Or the files are all listed but half of them open as a grey rectangle in your editor.
Before anything else: stop using that card. Do not shoot one more frame on it, do not let the camera rebuild it, and do not format it even when the camera insists. Most of the damage that turns a recoverable card into an unrecoverable one happens in the first hour, and it is nearly always something the owner did while trying to help.
This article explains what actually goes wrong with RAW files on memory cards, why partial recovery is normal rather than a failure, and what a realistic result looks like for the main RAW formats.
Stop Now, Then Do These Three Things
Lost and deleted files are usually still physically present on the card. What vanishes first is the index that points to them. What vanishes second is the data itself, the moment something new is written on top. Every extra frame you shoot, every camera-led "repair" of the card, every save of recovered files back onto the same card eats into the space your travel photos are still sitting in.
- Power the camera down and eject the card. Do not format it. Do not accept the camera's offer to rebuild, recover or initialise the card. Do not shoot a single test frame to check whether it still works.
- Label it and put it aside. Write the trip on a sticky note, put the card in a separate case, and stop treating it as a card you own. Treat it as evidence.
- If you try software yourself, work on a copy. Make a full sector-by-sector image of the card to a hard drive first, then point the recovery software at the image file, never at the card. If the tool cannot make an image, it is the wrong tool.
If the card is not recognised at all, shows as 0 bytes, or the reader does not see it, no software will help. That is a hardware-level fault in the card's controller or memory, and it needs SD card recovery in a laboratory rather than another download.
Why RAW Files Behave Differently to JPEGs
A JPEG from the same camera might be five or eight megabytes. A RAW frame is usually tens of megabytes, and on high-resolution bodies it can be well over a hundred. That size difference is the whole story.
Large files do not always land in one continuous run on the card. When you shoot a burst, the camera empties its buffer as fast as the card will take it, and the card's own controller decides where each block physically goes. Add a card that has been filled and emptied over several trips, a few in-camera deletions of rejected frames, and a RAW plus JPEG pairing that writes two files per shot, and the free space becomes patchy. A single RAW file can end up scattered across the card in pieces.
That matters because recovery software, when the file system index is gone, falls back on carving: it scans the raw contents of the card looking for the byte signature that marks the start of a known file type, then reads forward until it guesses the file has ended. Carving works beautifully on small, unfragmented files. On a fragmented 60 MB RAW file it will happily reassemble the first piece with whatever happened to be sitting next to it, and hand you a file of exactly the right size that is half photograph and half something else.
This is why partial recovery is the normal outcome on a badly damaged card, not a sign that something went wrong. The same principle applies to deleted file recovery generally: the bigger the file, the more of it has to survive intact and in order.
Recovering the File Is Not the Same as Recovering the Photograph
This is the distinction most people have never had explained to them, and it is the one that decides whether you are happy with the result.
A recovery tool that reports "4,182 files recovered" is reporting how many file-shaped things it produced. It is not reporting how many of them open. In practice recovered RAW files fall into three groups:
- Fully valid. The file is byte-for-byte what the camera wrote. It opens, it converts, it edits normally. This is the majority of the result on most jobs.
- Opens with damage. The header and the first part of the image data survived, the rest did not. You get the top third of the frame and then noise, magenta banding, or a hard cut to grey. Some converters will show it, others refuse it entirely.
- Header and preview only. The structural part of the file is intact but the sensor data is gone or unreadable. You get the EXIF, the date, the lens, and the JPEG preview the camera embedded inside the RAW file.
That last group is worth more than it sounds. An embedded preview is a real photograph. It will not take heavy editing and it is not the full-latitude file you shot, but for a trip you cannot repeat, a usable image of the moment is a very different thing from nothing. Part of the work in the laboratory is deciding, file by file, whether to hand back the broken RAW, the extracted preview, or both.
CR3, NEF, ARW, RAF and DNG: What the Format Changes
Every manufacturer wraps sensor data in its own container, and the container design decides how gracefully a file degrades when part of it is missing.
| Format | Typical camera | What it means for recovery |
|---|---|---|
| CR3 | Canon, recent bodies | Structurally closer to an MP4 container than to a TIFF. The index describing where the image data sits is part of that container, so a truncated CR3 often refuses to open at all even when most of its bytes survived. |
| CR2 | Canon, older bodies | TIFF-based and more tolerant of a missing tail. Header, EXIF and embedded preview usually survive together. |
| NEF | Nikon | TIFF-based with a JPEG preview embedded near the front of the file, so where sensor data is lost the preview can frequently still be extracted as a usable image. |
| ARW | Sony | TIFF-based. Compressed variants degrade sharply, because losing part of a compressed stream costs you everything after the break, not just the missing piece. |
| RAF | Fujifilm | Uses its own header holding offsets to each internal block. If the header survives but a block does not, converters tend to reject the file outright rather than show a partial frame. |
| DNG | Adobe, Leica, Pentax, some phones | Publicly documented and TIFF-based, which makes it the most forgiving to rebuild by hand when the structure is damaged. |
Two practical consequences. First, a card carrying a mix of formats can produce very uneven results, and that is the format's doing rather than the card's. Second, the fact that your converter will not open a file does not always mean the data is gone; sometimes the structure around the data needs rebuilding before any converter will look at it.
Why Cards Corrupt: Mid-Write Removal and Low Battery
Writing a photo is not one action. The camera writes the image data, then updates the file system tables that record the file's name, size and location. On the exFAT and FAT32 file systems cards use, those are separate operations a moment apart.
Pull the card out between the two, or let the battery die mid-burst, and the card is left in a contradictory state: data present with no entry pointing at it, or an entry pointing at a file that was never finished. The camera then reports the card as unreadable or asks to format it, and the last few frames of the day are the ones most likely to be affected.
There is a second layer underneath. Every card has a controller that maintains its own translation table, mapping the addresses your computer asks for onto the physical memory blocks where data actually lives, moving blocks around for wear levelling as it goes. If power is cut while that table is being updated, the card can lose its ability to present any coherent data at all. A card that suddenly reports the wrong capacity, or 0 bytes, or is not recognised by any reader, usually has a controller-level problem, and no amount of scanning software will reach the photos.
Common contributors, especially on a trip: a marginal or counterfeit card bought in a hurry, a camera powering down as the battery indicator hits empty during a burst, ejecting from a laptop without unmounting, and heat and humidity on a card left in a bag all afternoon. The best protection is boring: offload every evening onto an external hard drive as well as the laptop, and rotate cards rather than filling one.
What Not To Do With a Card Full of Travel Photos
Each of these makes a recoverable card measurably worse, and we see all of them:
- Do not format, even when prompted. A quick format usually leaves the data in place but discards the map to it. A full format writes across the card and ends the discussion.
- Do not run CHKDSK, Disk Utility First Aid, or any "fix the drive" option. Repair utilities write to the volume to make it consistent. On a damaged card that can turn recoverable RAW files into unusable fragments.
- Do not run five free tools one after another. Many write temporary data or their own recovery database, and each pass reduces what the next one can find.
- Do not save recovered files back onto the same card. This overwrites the files still waiting to be found. Always recover to a different drive.
- Do not let the camera rebuild the card. In-camera recovery rewrites the file system on its own terms.
- Do not apply heat, rice or a hair dryer to a wet card, and do not put a physically cracked or bent card back into a reader. Forcing it can short the controller and cost you the memory itself.
- Do not prise open a microSD card. These are monolithic: controller and memory are moulded into one block, with no separable chip to lift. Opening one destroys it.
If you have already done one or two of these, say so when you bring the card in. It changes how the card is approached, and it is far better known than discovered.
What a Realistic Outcome Looks Like
Set expectations this way. If the card is electrically healthy and the problem is a lost or damaged file system, the odds of getting most of your RAW files back intact are good. If the card has been shot on since the loss, expect gaps, and expect them to fall on the oldest material. If the card itself has failed, the work moves to board-level and chip-level handling in our own Singapore laboratory, and results depend on the state of the memory rather than on any software.
Where physical work is needed, it is done only to make the card readable long enough to take a full image of it. What you receive is your recovered files, not a working card. Assume the card itself is finished and buy a new one.
How the job runs at CBL, with more than 20 years and over 140,000 recoveries behind it: diagnosis is free, and we work from an image of the card rather than the card itself. You are shown the list of recoverable files, including which RAW files are fully intact and which are partial, before you pay anything. You get a fixed written quote before any work starts, and on standard cases it is no recovery, no fee. Everything is handled in line with Singapore's PDPA, and NDAs are available on request. If you want a sense of pricing before you come in, the data recovery cost page sets out how quoting works.
Bring the card to 6 Harper Road, Leong Huat Building #05-02, beside Tai Seng MRT, or send us the details through the contact form first. Bring the camera body as well if the card was still in it when the fault appeared; knowing the exact model tells us which RAW variant to expect.