Leigh Whannell chose not to have an opening establishing Cecilia's predicament with Adrian "because I wanted to just drop the audience into Cecilia's situation without any back story and make them feel everything through her, and luckily I had Elisabeth Moss who is very good at communicating a lot to the audience without saying anything."
Leigh Whannell had told cinematographer Stefan Duscio that this horror movie would feature plenty of light as an invisible man doesn't need to hide in the darkness, "and he kind of groaned with pain" because cinematographers love darkness. The attic scene is a "little gift" that he gave to Duscio, and they lit it with just the torch.
Leigh Whannell and his crew used a combination of old-school techniques and state-of-the-art CGI wizardry to bring the Invisible Man to life, with some scenes requiring a fully-green-suited actor that could be painted out later and others achieved with nothing more than a simple bit of string. "Well with, say, the fight scenes, that was a real mixture of things," Whannell said. "We had Lizzie being pulled around in wires. We had a stunt person in a green suit, who then had to be removed digitally. But then also in those scenes we would also use really old school practical effects like pulling doors closed with a piece of string. Some props guy would be hidden in a cabinet, and he would pull this piece of string and a door would close or a cabinet would open. It made you realise that how you do a visual effect doesn't matter - it's only the end result that matters."
As a fan of opening title sequences Leigh Whannell wanted this film to feature titles that are simple yet still speak volumes about the film itself. The one here - waves crashing against the rocks briefly showing the titles before they drip away - came to him on-set, and he soon discovered that water is the most difficult thing to get right with CG.
The character of Adrian's brother, Tom (Michael Dorman), is meant to feel as if nothing about him fits, and that's made literal in his costume. His suits are a couple of sizes too small to complete that subtle image, and Dorman loved it.