Influence of silent film and modern art
Kurosawa's admiration for silent film and modern art can be seen in the film's minimalist sets. Kurosawa felt that sound cinema multiplies the complexity of a film: "Cinematic sound is never merely accompaniment, never merely what the sound machine caught while you took the scene. Real sound does not merely add to the images, it multiplies it." Regarding Rashomon, Kurosawa said, "I like silent pictures and I always have... I wanted to restore some of this beauty. I thought of it, I remember in this way: one of techniques of modern art is simplification, and that I must therefore simplify this film."
Accordingly, there are only three settings in the film: Rashōmon gate, the woods and the courtyard. The gate and the courtyard are very simply constructed and the woodland is real. This is partly due to the low budget that Kurosawa got from Daiei.
Kurosawa's relationship with the cast
When Kurosawa shot Rashomon, the actors and the staff lived together, a system Kurosawa found beneficial. He recalls "We were a very small group and it was as though I was directing Rashomon every minute of the day and night. At times like this, you can talk everything over and get very close indeed".
The cinematographer, Kazuo Miyagawa, contributed numerous ideas, technical skill and expertise in support for what would be an experimental and influential approach to cinematography. For example, in one sequence, there is a series of single close-ups of the bandit, then the wife, and then the husband, which then repeats to emphasize the triangular relationship between them.
Use of contrasting shots is another example of the film techniques used in Rashomon. According to Donald Richie, the length of time of the shots of the wife and of the bandit are the same when the bandit is acting barbarically and the wife is hysterically crazy.
Rashomon had camera shots that were directly into the sun. Kurosawa wanted to use natural light, but it was too weak; they solved the problem by using a mirror to reflect the natural light. The result makes the strong sunlight look as though it has traveled through the branches, hitting the actors. The rain in the scenes at the gate had to be tinted with black ink because camera lenses could not capture the water pumped through the hoses.
Symbolic use of light
Robert Altman compliments Kurosawa's use of "dappled" light throughout the film, which gives the characters and settings further ambiguity. In his essay "Rashomon", Tadao Sato suggests that the film (unusually) uses sunlight to symbolize evil and sin in the film, arguing that the wife gives in to the bandit's desires when she sees the sun. However, Professor Keiko I. McDonald opposes Sato's idea in her essay "The Dialectic of Light and Darkness in Kurosawa’s Rashomon". McDonald says the film conventionally uses light to symbolize "good" or "reason" and darkness to symbolize "bad" or "impulse". She interprets the scene mentioned by Sato differently, pointing out that the wife gives herself to the bandit when the sun slowly fades out. McDonald also reveals that Kurosawa was waiting for a big cloud to appear over Rashomon gate to shoot the final scene in which the woodcutter takes the abandoned baby home; Kurosawa wanted to show that there might be another dark rain any time soon, even though the sky is clear at this moment. Unfortunately, the final scene appears optimistic because it was too sunny and clear to produce the effects of an overcast sky.
Stanley Kauffmann writes in The Impact of Rashomon that Kurosawa often shot a scene with several cameras at the same time, so that he could "cut the film freely and splice together the pieces which have caught the action forcefully, as if flying from one piece to another." Despite this, he also used short shots edited together that trick the audience into seeing one shot; Donald Richie says in his essay that "there are 407 separate shots in the body of the film ... This is more than twice the number in the usual film, and yet these shots never call attention to themselves".
The film was scored by Fumio Hayasaka, who is among the most respected of Japanese composers. At the director's request, he included an adaptation of "Boléro" by Maurice Ravel, especially during the woman's story.
Due to setbacks and some lost audio, the crew took the urgent step of bringing Mifune back to the studio after filming to record another line. Recording engineer Iwao Ōtani added it to the film along with the music, using a different microphone.