Using EOS 5Dii footage in Media 100

I'm trying to use footage from my EOS 5Dii in a Media 100 project but am really struggling to find a way of importing the DSLR footage without it looking really awful. I'm using MPEG Streamclip to convert the EOS files into Media 10 Pal Quick Time files. In Quick Time to files look lovely but once I import them into Media 100 they look awful - as if they were off-line. Is it at all possible to use this footage with M100 or am I wasting my time?

I'd really appreciate any advice. (I'm not very techy so keep it simple if you can!)

I'm using Media 100 Suite 1.6.2 in SD. (I don't have FCP so can't use Magic Bullet to convert the files to Apple ProRes which someone suggested as a solution.)

Sue Daly