Academy ratio

When sound-on-film was introduced in the late 1920s, the soundtrack was recorded in a stripe running just inside one set of the perforations and cut into the 1.33 image.

[1][2] This made the image area "taller", usually around 1.19, which was slightly disorienting to audiences used to the 1.3 frame and also presented problems for exhibitors with fixed-size screens and stationary projectors.

The first standards set for the new sound-on-film motion pictures were accepted in November 1929, when all major US studios agreed to compose for the Society of Motion Picture Engineers (SMPE) designated size of 0.800 in × 0.600 in (20.3 mm × 15.2 mm) returning to the aspect ratio of 1.33:1.

[1][2] 1.375:1 is not totally obsolete, nonetheless, and can still be found in select recent films such as Joel Coen’s The Tragedy of Macbeth (2021), Wes Anderson's The Grand Budapest Hotel (2014)[5] and Asteroid City (2023), Paul Schrader's First Reformed (2017),[6] Michel Hazanavicius's The Artist (2011),[7] Gus Van Sant's Elephant (2003),[8] Andrea Arnold's Fish Tank (2009), Kelly Reichardt's Meek's Cutoff (2010), Carlos Reygadas' Post Tenebras Lux (2012), and Don Hertzfeldt's It's Such a Beautiful Day (2012) as well on prints of Phil Lord, Christopher Miller's The Lego Movie (2014) and 4:3 prints of Steven Spielberg's Indiana Jones and the Kingdom of the Crystal Skull (2008) intended for 1.78:1 exhibition (a 2.39:1 version was also made).

The Academy ratio is not created in the camera, which has continued to use the full frame silent aperture gate for all 4-perf spherical filming.