828 film was a photographic film format introduced by Kodak in 1935. It was introduced very soon after 135 (35 mm) film and used the same film stock, but with a single sprocket hole per frame giving a larger picture image of 40 × 28 mm. Despite this, the format was targeted at the consumer market and never sold well.
The first camera to use the format was the Kodak Bantam, and there were several models of this, as well as the Kodak Pony that also used the format. The smaller size of the spool than the 135 film cartridge allowed for more compact camera designs.
The film came as a roll on a metal spool and used backing paper, like 120 film, with the the backing paper showing the frame number through a hole in the camera back. Each spool only carried eight exposures.
828 film was available in black and white, colour and reversal (slide) versions, but the last cameras to use it were discontinued in 1959 in the US, and 1963 in the UK. 828 film continued to be produced by Kodak until 1985.
To use an 828 film camera, it is possible to respool standard 135 film by reusing the spool and backing paper (however the sprocket holes will intrude into the image), to use unperforated 35 mm film, or to cut 120 film to size.