What IS RAW anyway?

Check out this thread at Rob Galbraith's forum:

Forum

Apparently there is some amount of processing done to all RAW files in all Canon dSLRs, which is contrary to the belief that RAW is exactly what the sensor sees. This even applies when using 3rd party RAW convertors, not just straight Canon software.

Doesn't really change a whole lot practically, but it was certainly interesting to read, lot's of people who's world went from round back to flat.

Tom

After readng the entire thread, I'm left feeling that not nearly enough was disclosed to support the conclusions and the Canon rep (chuck) was mostly likely a non-technical person.

I think the assumption that RAW files are non-processed is still a good one. Clearly the camera has to do some processing to read the image data from the sensor and that probably requires some signal processing work as part of the whole A-to-D thing to minimize noise. Whether sharpening is done or is beneficial before demosaic seems really weird to me. The assertion that chuck made that sharpening is always done because converters must do what the cameras don't is stupid. Using Spinal Tap-like numbers to describe the sharpening doesn't help, either.

I think an explanation of what these cameras actually must do prior to the RAW format would be really interesting. I doubt the manufacturers would be willing to share that and I'm certain it wouldn't come from a director within one of those companies. An interesting read, though.