Camera RAW (CR2, NEF, ARW)
Also known as: raw photo files, CR2 file, NEF file, ARW file
Camera RAW is the umbrella for manufacturer-specific files that store unprocessed data straight off the camera sensor — Canon CR2/CR3, Nikon NEF, Sony ARW, and others. They keep maximum editing flexibility, which makes them far larger than the JPEG or HEIC the same shot would produce.
- Unprocessed sensor data, brand-specific (CR2, NEF, ARW)
- Much larger than JPEG or HEIC of the same shot
- DNG is the open, vendor-neutral RAW alternative
What a RAW file holds
A RAW file records the sensor readout before the camera applies white balance, sharpening, or compression. Nothing is baked in, so an editor can recover highlights, shift color, and adjust exposure with little quality loss. Each brand uses its own extension — Canon CR2/CR3, Nikon NEF, Sony ARW, Fujifilm RAF, Olympus ORF — but they are all the same idea.
That flexibility costs space. Because the data is unprocessed and lightly compressed at best, a single RAW frame is many times larger than the JPEG of the same scene, and a shoot of a few hundred frames fills a card quickly.
Managing RAW storage
Most photographers keep RAW for keepers and edits but export to JPEG for sharing, since few apps open proprietary RAW directly. Apple’s open DNG format is a vendor-neutral alternative many cameras and phones can write instead.
If a library is full of RAW you no longer edit, archiving to an external drive or cloud and keeping only the final exports on-device recovers the most space.