Lesson 17: File Formats: JPEG, RAW, and Others

When you press the shutter, the camera must decide how to save the image, and the choice matters. The two formats every photographer should understand are JPEG and RAW. They are not two versions of the same thing: they represent different philosophies — convenience against control — and choosing between them is one of the first real decisions a photographer makes.

A JPEG is a finished photograph. The camera processes the sensor data — setting white balance, sharpening, contrast and colour — then compresses the result into a small file, discarding information it judges unnecessary. The result is ready to share immediately and takes little space: a JPEG is typically a few megabytes. The cost is that the discarded information is gone. If the exposure or white balance is wrong, there is limited room to fix it, and every time you re-save a JPEG it is compressed again, losing a little more quality.

RAW: The Digital Negative

A RAW file is the sensor's unprocessed data, plus the camera's settings as notes. Nothing is discarded and nothing is baked in: white balance, exposure, sharpening and colour are all decided later, on your computer. A RAW file is much larger — often 20 to 50 megabytes — and it looks flat and dull until edited, but it holds far more information, especially in the shadows and highlights. Photographers call it a digital negative, and the comparison is exact: like film, it is not the photograph, but the material from which the photograph is made.

The practical difference shows in difficult light. A JPEG of a sunset may have a white sky that cannot be recovered; the same scene in RAW often holds detail in those highlights, and shadow areas that look black in a JPEG can be lifted to reveal detail. White balance can be changed completely in a RAW file with no loss, while in a JPEG it is largely fixed. For any photograph you care about, RAW gives you a second chance at the exposure.

Other Formats and the Choice

Other formats fill particular roles. TIFF is a large, uncompressed format used for print and archiving. PNG is lossless and supports transparency, which makes it the choice for graphics and logos rather than photographs. HEIF is the modern format many phones use: it compresses better than JPEG at similar quality, but is less widely supported. Most cameras also offer a RAW+JPEG mode that saves both at once — the JPEG for quick sharing, the RAW for serious editing.

For a beginner, the sensible rule is: shoot JPEG while you are learning composition and exposure, and switch to RAW (or RAW+JPEG) as soon as you start editing seriously. Storage is cheap; a lost photograph is not.