Camera RAW files

I am a Nikon & Olympus user. Nikon RAW files are .nef & Olympus .orf. When I chose an nef file I can see a preview of it but NOT the Olympus orf file.
Now these raw files cannot be seen, just an embedded jpg file they all contain. I don’t know where TotalFinder picks up its info to display the preview but it would be nice to see the preview rather than an icon for my Olympus raw files.
All the photo apps & programs have now been updated to handle the Olympus files from their latest camera.