When the franchise first started filming in 2000, many of the special effects that made the wizarding world feel so magical were done using strings, wires, and wind machines, rather than the CGI we're familiar with today, which had its ups and downs. "One of my favourite moments on set was the moment when all the floating candles started burning through the ropes that tied them to the ceiling and just started falling around the great hall," Radcliffe recalled before Watson added, "Hundreds of real candles that were really lit on fishing line from the ceiling."
When CGI became more popular, effects like Voldemort's reptilian nose, which was created using special-effects stickers rather than makeup, became even spookier on screen. Later on, the special effects were so realistic that they even fooled actors like Richard Harris, aka Dumbledore, who fully believed that the animatronic of Fawkes the phoenix was a real bird.