Harry Potter: 10 Behind The Scenes Secrets That Will Blow Your Mind
4. Creating The Eerie Environment Of The Black Lake
Hogwarts is not just a safe haven for students, but for magical creatures that have a hard time hiding in Muggle-populated areas. The Black Lake on the grounds of the school is no exception, and comes filled with a variety of fantastic beasts that often go unnoticed.
From pesky little Grindylows to territorial Merpeople, it's no wonder students are advised to avoid swimming at all costs. But things changed for Harry when the Triwizard tournament came around, which made life a bit difficult for the cast members involved in filming these underwater scenes.
To make filming possible the production team had to build a large tank which they then filled with water. After having decorated the tank with various types of foliage, fluorescent lights were installed at its edges to ensure that there was enough light to film.
About three weeks of filming and a grand total of 40 hours spent underwater, the segment was finally complete and submitted for post-production review.
All that was left was for the VFX department to fill in the gaps with everything from spell effects to creatures of the deep, making the segment one of the most complex of any filmed in the franchise to date.