The film was shot in an anamorphic wide screen format called Regalscope, renamed "Hammerscope" by the company. Val Guest found it an unsatisfactory format to work in, which made getting in close to the actors difficult and required careful framing of scenes. This was the first film Arthur Grant worked on for Hammer as cinematographer and his reputation for being fast and cheap meant he soon replaced Jack Asher as Hammer's regular cinematographer. Just as he had done with the "Quatermass" films, Guest tried to give the film "an almost documentary approach of someone going on an expedition with a camera for "Panorama" or something". To this effect, he made extensive use of hand-held camera and overlapping dialogue.