Film projection businesses provide the equipment and technical services needed to show films to an audience. This may include supplying, installing or hiring digital cinema projectors, screens, playback systems and related sound equipment. Some providers also work with traditional film formats, such as 35mm or 16mm, where suitable projectors and handling skills are available. Services can cover setting up and testing equipment, adjusting image focus and alignment, connecting picture and sound systems, and operating projection during screenings. Customers may include cinemas, theatres, schools, community venues, film festivals and organisers of indoor or outdoor events. Depending on the provider, work may also include advice on choosing equipment, maintenance, troubleshooting and technical support for one-off screenings or permanent installations.