I've loaded up many hours of footage onto my iMac, and thought it'd be good to convert it all to Prores for the colour quality advantages (correct me if this is a lie, as I'm not that fussed about render speed). But now my HDD has gone from just over 200 GB to almost 900 GB, and it's a 1 TB HDD - basically I'm almost out. Much of my clips I don't want to keep, but I've found that FCP X doesn't delete that which I reject (again correct me if I'm wrong). Which leads me to my question: How can I effectively trim my clips down, minimise hard drive usage (i.e. rejected clips are completely deleted), whilst maximising footage quality? Raw footage is in 1080 MPEG-4 H.264, and I'm usually getting 1-2 hours, and trimming down to 1 min to 15 min with several (1-5) clips.