"A thousand times these words have bellowed from my mouth, and it will surely come out a million more. Raw is an unmodified compilation of your sensors data during the time of exposure. It is your digital negative. When you shoot in JPG format, everything but what the image processor needs to make a shell representation of the image you intended to capture is stripped away. For every edit you make to a JPG, you lose more data. With RAW, you can make a vast range of edits before creating the JPG. How can this make you portrait better? Think about the last time your white balance was set incorrectly, and you tried for hours to remove the color cast only to destroy the image with every attempt. RAW would have saved you by allowing you to fix the color before opening the image for retouching."