I did some initial ratings in FastRawViewer and then brought the Sony ARW files into PL3 where I changed some ratings after looking at them again. I wanted to move them to another folder but I can’t as ARW. It has to be DNG?
So I went back to FRW but didn’t see the newly rated images.
So two things. Ratings that happen in PL3 stay in PL3? And you can’t export a RAW file in anything but DNG?
Star Ratings
FastRaw Viewer writes star ratings into an .xmp sidecar file.
PhotoLab reads the star rating from the sidecar and displays it as gold stars.
When you change the rating in PL…
PL reads some foreign metadata but it can only write it to its own .dop sidecar files as well as into non-raw files like jpeg, tiff and dng.
File Export
PhotoLab offers to export the documented file formats. As of today, they are jpeg, tiff and dng. Note that PhotoLab cannot display the dng files it created 
OK thanks. If I go back and change the star rating in FRV after PL has seen it should PL see the new rating. It doesn’t seem to now.
In fact I also tried changing the rating in iMatch, wrote it back to the XMP, but PL didn’t pick it up.
I think once PL has created a .dop sidecar, it will use that for the star ratings. If you remove the .dop file, I’m guessing the .xmp rating data will be pulled in again.
I’ve changed the rating in FRV a few times and found that DPL shows changes in less than a second.
Note: I’m on Mac.
There’re two different ratings in PL3. there’re yellow ones that say they’re from the XMP file and plain ones which say created in PL3. I’ve gone back to FRV and changed ratings (FRV writes to the XMP) but I don’t see that change in PL3 on my Win 10 machine.
I think I’m going to try culling and rating everything in iMatch and avoid touching metadata anywhere else.
Tobe clear, if you didn’t know.
FRV creates a XMP file where the starrating is placed.
PL can read xmp’s but not, yet, write in them.
So your change in rating is only Database stored. The xmp isn’t changed.
The only way data can be transfered from xmp to the properies of the image is a export in PL.
So , IPTC, EXIF,XMP data can be read by PL but not editted and stored in a sidecar as XMP is.
Got it. Thanks.
Probably all the more reason for me to leave metadata alone outside of iMatch.
… good idea anyway. Stay focused with the task at hand with the tool that does it best.
PhotoLab’s home turf is with optical corrections, NR and color rather than with asset management.