I’ve placed a couple of short sample raw files in my drop box for anyone that want’s to have a play. These were deliberately over exposed by 2 stops so you can experiment with grading them. I recommend you try DaVinci Resolve 9 or higher, the free Lite version is fine. If you can’t or don’t want to use Resolve you can also use the free Sony Raw Viewer. There are limits to how many downloads drop box will allow in a day so if the link becomes unavailable please try the next day.
https://www.dropbox.com/s/ftjuq61uwxn8m71/f55-raw-samples.zip