Fundamentals
Photo recovery: JPG and RAW in detail
With RAW files a visible preview proves nothing. It can even mislead.
The short answer
With RAW it is the sensor data that decides, not the preview.
A CR3, ARW or NEF file contains an embedded JPEG preview. That preview can be perfectly readable while the actual sensor data is missing. A tool then displays an image that cannot be developed later. Every RAW file must therefore be opened in a converter before it counts as recovered.
01 / Formats
What sits behind the extensions
The TIFF-based formats share a common layout. A tool that reads TIFF structures therefore often recognises all of them — which does not mean every recognised file is complete.
| Format | Structure | What to check |
|---|---|---|
| JPG / JPEG | One image, compressed, usually contiguous | Open fully, watch for artefacts at the bottom |
| CR3 (Canon) | Container format, built like MP4 | Develop in a RAW converter, do not just look |
| CR2 (Canon, older) | TIFF based | Compare file size with other frames in the series |
| ARW (Sony) | TIFF based | Judge preview and sensor data separately |
| NEF (Nikon) | TIFF based | Check for complete metadata |
| DNG | Open RAW format | Checksums inside the format can give hints |
| HEIF / HEIC | Container format | Treat like video: verify the structure |
02 / Procedure
From card to verified photo
- 1
Take the card out of the camera at once and stop shooting.
- 2
Create an uncompressed image of the card and work only with that.
- 3
Scan deliberately for the formats actually used, for instance JPG plus CR3.
- 4
Export to a different drive and keep the original structure.
- 5
Develop every RAW file fully in a converter; do not just check the preview.
- 6
Check series for gaps using the number range and the timestamps.
03 / Verify
How to recognise a complete photo
- The file opens and develops fully in a RAW converter or image application.
- The file size sits in the range of other frames from the same camera and settings.
- The image shows no grey blocks or colour banding along the bottom — a classic sign of truncated data.
- The metadata contains camera model, lens, exposure values and capture time.
- In a series, no numbers are missing between the first and last recovered frame.
When your file manager shows a thumbnail, it often comes from the RAW file's embedded preview. That says nothing about the sensor data. Never rely on the operating system's thumbnail.
04 / Limits
What software cannot do either
If shooting continued after the loss, the overwritten areas are permanently gone. A partly overwritten RAW file cannot be reconstructed, because the missing sensor data no longer physically exists.
File Recovery Hero examines stable, readable exFAT, NTFS and FAT16/FAT32 devices and uncompressed images. APFS, HFS+, ext4, encrypted storage and physical damage are outside the scanning scope. Repairing individual damaged photo files is also not part of the product.
Common questions
My image application displays the RAW file. Is it recovered?
Not certain yet. Many applications first show the embedded JPEG preview. Develop the file fully in a RAW converter — only when that succeeds is the sensor data demonstrably present.
Why are some recovered JPGs grey at the bottom?
That is the classic look of a truncated file: the start is intact, the end is missing. Often the later part was already overwritten. Such images cannot be fully recovered.
Can I recover photos from the camera's recycle bin?
Cameras generally have no recycle bin. Deleting in the camera releases the storage directly. That is exactly why it matters not to keep using the card afterwards.
What about photos in a Lightroom catalogue?
A catalogue stores references and edits, not necessarily a copy of every original file. Check the last known original path and your backups before starting a recovery scan.
Can I recover photos after taking more pictures?
Possibly in part, but only from areas that have not been overwritten. Stop using the card and check recovered images individually in full; every new picture can displace more data.
Should I run the camera repair function before recovery?
No. A repair or initialisation writes management data to the card and can change the starting state. Create an image first and attempt recovery from that copy.
Your photo format in detail.
CR3, ARW, NEF and JPG each have dedicated walkthroughs.