Answer is in „invisible“ visual effects. For film Hanna were been created by visual effect studio Mr X. Hanna is the new movie from Director Joe Wright about a teenage girl being raised by her father, an ex-CIA agent, in the wilds of Finland. That is the reason why she knows how to use guns, martial arts and how to survive.
To improve this movie was asked Mr X. Mr X's work spans across 200 VFX shots that range from snow enhancements to tricky compositing techniques to full matte paintings and CG environments. Brendan Taylor, the visual effects supervisor of Mr X, shares with us the experience working for the movie. He describes how they created some interesting scenes e.g. Berlin Windkanal, Death of a Reindeer, fighting sequences and others.
To more about this movie and secret of Mr X`s work you can read here: deathfall.com