It's a good beginner's article, but doesn't (probably can't) say much about how different sensors record the data, what the camera manufacturer does with the sensor data before producing the RAW image, etc. I was hoping someone would remember the info I read a couple years ago about the number of bits of color space (or something like that) that are available in RAW's -vs- JPEG's, or if that's not always different, whether Panasonic, for example, is not doing as good a job with their LX3 product as they did with their FZ50.
Most digital cameras encode the raw data in a linear fashion (gamma = 1.0), where the output data number is proportional to the luminance, and use a bit depth of 12 or 14 bits. JPEGs are usually 8 bits per channel with a gamma of 2.2. Twelve, fourteen, and 8 bits correspond to 4096, 16384, and 256 levels respectively. When converting from a gamma of 1.0 to 2.2, levels are lost as can be demonstrated by Bruce Lilndbloom's
levels calculator. As Norman Koren
explains, an 8 bit image at a gamma of 2.2 can usually encode the dynamic range of a typical photograph, but just barely. If your exposure or tone curve is less than optimal, your image will suffer when you edit it. However, if you are shooting raw at 12 or 14 bits, you may still have enough levels to get a good image. Although white balance can be adjusted in JPEGs, it is best done with the raw data where you have more levels to work with.
In view of the above, if your exposure, white balance, and tone curve are perfect, a JPEG may be fine; however, if these parameters are less than perfect, a raw file gives you much more flexibility.
Color gamut is also a consideration. Most digital cameras offer only aRGB or sRGB with JPEG output. Modern digital cameras can capture a considerably higher range of colors than these spaces can accommodate, and modern inkjet printers can print some of these colors. To take advantage of the capabilities of your camera, it is best to shoot raw and render into 16 bit ProPhotoRGB or a similar wide gamut space. This option is not available in JPEGs.
Finally, sharpening and noise reduction are important considerations and these parameters are baked into a JPEG conversion. The camera applies a global unsharp mask to the image, whereas modern sharpening techniques use masks and blending options to produce better results.