Hitfilm 3 Express, Windows 7, 16GB ram, i7 4770k 4Ghz, AMD 7950 GPU, 3GB ram, driver 15.7
I opened the "portal tutorial project" downloaded from the Hitfilm website. Open any of the three composite shots and select "Half" in the viewer options and you can see the dimension rift effect has some problems. The whole thing changes size. Okay at full. Not okay at Half and Quarter.