This may be a really stupid question, but when I open a RAW file, it also adds an XMP file....what does this mean? I am getting ready to back up my files on to my new external hard drive ( ) and I don't know if I need those or not....
The xmp file records the alterations you make to the RAW file in ACR or Lightroom. If you delete them, you lose any metadata and changes you make to the files.
Wife to Rich~ 8/16/03 Mom to Nathan~ 9/30/07
If you are going to delete the photo, you don't need the XMP file. However, if you've made a lot of changes in ACR or the like (for example, changes in white balance, exposure, etc), then you'll want to back up those files with its corresponding RAW file.