JPEG vs. RAW

A question often asked when first introduced to professional Photography is, "What is the difference between shooting JPEG and shooting RAW?" First, lets consider how a photograph is made: you press a release, which opens the shutter, which allows light to reach a plane, which "exposes" a digital sensor. From here, the image is saved to your supported format.

A JPEG image is a compressed file. The objective is to process the image in a way that causes no quality loss visible to the human eye. In other words, the camera is saying "I don't need this data in order to show you an accurate image." This is great because it allows for small file sizes, and beautiful images. A standard 15mp image will be about a 4MB file. So did you catch that? The image is processed before it leaves your camera.

Every thing has a positive and a negative. No matter how you take it, JPEG is a lossy compression format. And each time you process the image, it loses considerable quality. What most are not conscious to is that the original image has already been processed once, in-camera. So when you edit that image, you are already re-compressing the file. This is where the term "post" processing originated (digitally at least). Another problem is that editing introduces artifacts which can soften or otherwise distort the image. It's like a one way valve, once the data is gone, it's not coming back.

Then we have the RAW format. A RAW file is uncompressed. No camera processing is done to the image after it is captured. That means you are starting with the original (like a negative), and have complete control over how the image is processed. There are obvious benefits to this such as the ability to make adjustments, especially white balance, without any loss in quality. On the other hand, a RAW file will take up about 5 times the space of a JPEG.

If you need the highest quality image, shoot RAW. At the very least, it provides one less round of processing (assuming you will be editing the images). If you are going to deliver pictures straight out of the camera, there is no need to shoot RAW. JPEG is a great format, but it wasn't born to edit; it was born to specify a codec in which images can gracefully be compressed.