In order to select the locations, Terry Gilliam used Google Earth: "I'd got most of the locations sorted out by using Google Earth before I first went to Romania. This is how we do location scouting these days."
The film's production budget used to be $20 million, when it was planned to shoot in London, UK. Later it was decided to move the production to Bucharest, Romania, and the movie finally could be made for only $8.5 million.
Cinematographer Nicola Pecorini decided to shoot on film rather than digitally: "Both Terry and I were convinced that the best way to capture the image was on film. It gives you the latitude; it gives you the greatest palette to work with." The 35mm negative was processed and digitized overnight by Kodak Cinelabs Romania located nearby in the center of Bucharest. Digital rushes were available to view in the morning.
The film was finished in a 16:9 aspect ratio instead of the usual 1.85:1 or 2.35:1 to ensure that it would look exactly the same on the screen of any device. Additionally, it has round edges on the frame corners like a vintage movie. Together this creates a very distinct-looking image, a unique mix of 'old' and 'new' aspect ratio designs.
The name "Qohen Leth" references "Qoheleth" (sometimes transliterated as "Qohelethin" or "Koheleth"), the original Hebrew name (and presumed author) of Ecclesiastes--the Bible book that investigates the meaning of life.