On Sun, 7 Mar 2004, Tanya Mayer Photography wrote: > Can someone explain to me exactly how RAW works? I understand that it gives > you a file that is captured exactly as you see it, without colour > correction, compression etc. Does this also mean that the > contrast/saturation/sharpness/noise reduction settings on the camera are > irrelevant?
No. Those settings are saved in the file, and the RAW processor (the good ones at least) will use those settings in processing the image. However you can override them in the software, something which you can't do when shooting JPEG. > How do the changes you make in the Plug In software (eg, > saturation/contrast)differ to when you make the same adjustments within PS? They are done before the image has been processed at all. As an example, imagine that you shot the image at high contrast and wanted to make it lower contrast for printing. Using photoshop you can't really do this, the highlights and shadows were already blown by the contrast setting. You can turn the contrast down, but you won't get those details back. With the RAW convertor you can just go select low contrast and have it reprocess the image. All of the data that was ever captured is in that RAW file, so you can adjust the exposure some more to get the highlight or shadow detail that you want. Obviously there is a limit. I think of it somewhat as the difference between shooting slide film and negative film. JPEG is like slide film, going back and making exposure (or color balance) changes is probably going to result in some artifacts. With RAW you have a little more exposure latitude and can correct (to some degree) for shooting mistakes in the RAW conversion process. alex
