[ Thanks to Carla
Schroder for this link. ]
“Lower-end digital cameras support only JPG. Higher-priced
cameras support JPG, RAW, and sometimes TIFF. This is an artificial
distinction as lower-priced cameras can shoot RAW just like their
more expensive siblings. When some brainiac figures out cool hacks,
as with CHDK, the Canon Hack Development Kit for Canon
point-and-shoot cameras, all kinds of advanced features are
unlocked.“JPG is a lossy 8-bit file format. At 8 bits you have 256
brightness levels. The camera, which is really a little computer,
manipulates the sensor data to create the photo: white balance,
contrast, brightness, and color hue and saturation. Then it applies
whatever compression level you have set. A higher compression ratio
results in smaller file sizes, and that smaller size comes at a
cost of throwing away information.“RAW files are minimally-processed sensor data. There isn’t a
single RAW file format, because all the camera vendors like to use
their own special secret RAW formats. The big “secrets” are headers
and image metadata such as date, exposure, and ISO settings. Most
RAW files are based on the TIFF file format.”