RAW image
/rɔː/ · noun · image format family
A RAW image is the unprocessed sensor data a camera saves, plus metadata and a small preview. It needs developing before it becomes a normal picture.
In more detail
A RAW file stores the brightness each pixel of the camera sensor measured, before the camera applies white balance, colour, sharpening and compression. It keeps far more information than a JPG, which is why photographers edit from RAW.
Each camera maker has its own format: CR2 and CR3 for Canon, NEF for Nikon, ARW for Sony, RAF for Fujifilm, ORF for Olympus and OM System, RW2 for Panasonic and PEF for Pentax. DNG is Adobe's openly documented RAW format, used by Leica, DJI drones and many phones.
Developing a RAW file
Turning RAW data into a picture is called developing, after film. Software reconstructs full colour from the sensor's colour filter pattern, sets the white balance and exposure, applies a tone curve and saves a JPG or TIFF. Doing this yourself lets you recover highlights, fix colour and choose the look.
RAW files also carry a JPEG preview rendered by the camera. Viewers show that preview so they don't have to develop the file, and converters can extract it to get a JPG in an instant.
RAW or JPG?
RAW files are larger and need software that supports your camera, but they give you room to correct mistakes. JPG files are small and open anywhere, but the camera's choices are baked in. Many photographers shoot both, or shoot RAW and export JPGs to share.
Key points
- RAW files hold unprocessed sensor data and are developed in software.
- Each camera brand has its own format, and DNG is an open alternative.
- Most RAW files include a camera-made JPEG preview you can extract.