The version of RAW used by my camera is NEF, the Nikon raw.   There is an option to compress the data and Nikon says there will be little loss of quality.

I have used both compressed and full file and have not seen loss of quality, or at least not a loss I have recognized.       Compression is slightly less than 1/2, such as from 15mb to about 8mb.

Any thoughts on compressing RAW in camera or leaving it at full size file?        TomDart.