
Dumbledore’s Office

Dumbledore’s office, all those old books of great magic, wisdom and secrets were in fact very old phone books covered in leather and let to stay in a dusty environment to show age and maturity.
Yule Ball Scene

You remember the Yule Ball scene, where Harry had to dance. While other cast members had weeks of training, Radcliff had only four days, due to his tight filming schedule. For that reason all his scene are shown waist up. Obviously, to not give away any stumbling feet from below.
The Library Scene

In the first installment, ‘Harry Potter and the Philosophers Stone’ – the library scene revolving around going into the restricted section.
The Duke Humfrey’s Library made an exception of a massive scale, for that particular scene. Because the library historically forbids flames and the scene required Harry to carry a traditional flame lamp in his hand and walk.
A Giant Spider

The scene involving Ron watching Aragog (a giant spider), the horribly frightening expressions you see were completely natural due to his acute fear of spiders in reality – arachnophobia.
Students Passing Through Walls

Students passing through walls, wall mounted lanterns and torches was all simulated through the use of more than 300 fiber optic lighting, installed in the Hogwarts model. Not everything you see is digital, and that’s where all the fun of realism comes from.
Sorting Hat Scene

Remember the sorting hat scene, when Harry, Ron, and Hermione enter the great hall for the first time.
The trio had never seen the hall before, ever! The aw’s and amazement was as real as it could get from the actors.