01In plain English
A raw file keeps everything the camera sensor captured, before any sharpening, color or compression is applied. It has to be developed in a raw editor, where you set exposure, white balance and color yourself.
02How it works
When you take a picture on a phone, the camera quickly applies sharpening, color and compression and saves a small JPEG. A camera set to raw skips most of that and writes out what the sensor recorded. The file is large and looks flat when you first open it, because nothing has been decided yet. You open it in a raw editor, which develops the picture: you set the exposure, the white balance, the contrast and the color, and then export a JPEG or another format. Because all the sensor data is still there, you can pull detail back out of a bright sky or a dark corner. It is the difference between a printed snapshot and the film negative you can reprint.
03Why it matters when you are choosing
Raw files let you recover blown highlights and dark shadows and fix white balance without losing quality. If you shoot raw, a raw editor matters more than any other feature.
04What to check
Check that the editor supports your camera model, and whether it also organizes a large photo library or only edits one image at a time.
05Where you will meet it
06Common questions
Is shooting in raw worth it?
If you edit your photos, yes. Raw gives you far more room to fix exposure and color without visible damage. If you only share photos straight from the camera, the large files and extra step are not worth it. Many cameras can save both formats together.
Why is a raw file so much bigger than a JPEG?
A raw file keeps all the sensor data with little or no compression, while a JPEG throws away detail to shrink the file. The extra data is what lets you recover highlights and shadows. It also means you need more storage space and a raw-capable editor.
Can I open raw files without Photoshop?
Yes. Many editors read raw files, including free ones, and your operating system may show a preview. Each editor supports a list of camera models, so check that yours is included. Support for a camera usually has to be added for each model.