If you just bought a new camera like Canon EOS-1Ds Mark III you won't be able to process your RAW files without proper software. Each camera manufacturer that uses the RAW format does it in a slightly different way, and this can change even with different models from the same manufacturer. If you use RAW-conversion software like ImageConverter Plus, make sure it will work with your particular camera model. ImageConverter Plus is able to batch process and automate conversion steps for RAW files from lots of cameras including Canon EOS-1Ds Mark III. If you want to reproduce your images in quality publications or as quality color prints, then the RAW format is almost mandatory. This is the only way to go for a photographer concerned primarily with image quality.