The need for professional projectionists arose from the commercial showing of movie films to the general public in buildings specifically designed for the purpose or using variety theatres as part of the "bill", which began towards the end of the first decade of the twentieth century.

Before the emergence of purpose-built movie theaters, film projectors in venues such as fairgrounds, music halls and Nickelodeons were usually operated by a showman or presenter, in the same way as a lanternist.

With nitrate went the restrictions on reel lengths previously necessitated by the fire risk, with the result that systems were developed to enable the projection of a complete feature film using a single, unattended projector.

Automation systems were also introduced, which could be programmed in advance of each screening to perform functions such as operating auditorium lighting, adjusting volume levels and changing audio formats.

Some would argue that these technologies reduced the skill level or downgraded the showmanship element of the projectionist's job (for example, by eliminating the need for changeovers and nitrate handling precautions).

With the introduction of widescreen in the early 1950s, projectionists had to cope with the additional lenses, aperture plates and masking systems needed for different aspect ratios for the first time.

Like nitrate film prints, xenon arc bulbs require special safety precautions: if handled incorrectly they can explode,[8] causing serious injury to the projectionist.

In the classical "movie palace", the labour-intensive nature of changeovers, carbon arc lamps, and nitrate handling required large workforces of projectionists, with up to six or seven working in a single booth[citation needed] and a rigid management hierarchy within the profession being common.

[10] In order to avoid paying a higher wage rate and to circumvent skilled labor laws, some companies (such as Cinemark Theaters) use the job title "Booth Usher" for an employee who simply carries out basic screening operations and does not perform any program assembly, maintenance or repair procedures.

As of November 2010, the major chains in the US and Europe are in the process of a large-scale conversion to digital projection, in some ways comparable to the mass installation of sound equipment in the late 1920s and early 1930s.

[13] The basic operation of digital cinema servers and projectors requires little more than routine IT skills and can be performed by a theatre's front-of-house and managerial staff with minimal extra training.

Within a few years, it is likely that projectionists, in the traditional sense of the word, will only be found in the small number of arthouse, cinematheque and repertory theatres that will continue to show film prints from archival collections.