Progress in micro-electronics has led to an increasing number of automated cameras. Whereas once automation was an expensive option and basic cameras were manual, electronic automation has now taken over most areas of camera marketing so that even the simplest models have some automated features.
The first application is exposure control, in which the shutter speed and/or aperture are set automatically. Others include focusing, film winding, film loading, and electronic flash control. Among the cheaper compacts and mid-range cameras, this automation generally simplifies their appearance and operation, but among high-end models it can result in a proliferation of displays and controls.
There are always occasions when the photographer needs to exercise full control over exposure and focus. The extent to which this is important depends on the type of photography, but there is clearly an advantage in being able to override whatever automatic systems exist. Non-automatic cameras are a rarity today, except for the least expensive snapshot models, but a 35mm automatic, designed for serious use, should allow the photographer to by-pass the automatic controls if necessary.
The choice, therefore, is usually not between automatic and manual, but between different levels of automation. In a well-designed, high-end camera there may be three levels: 1) specific programmed modes that the photographer must select, and which each cope with one kind of photography (such as close-up or sports). 2) standard automation, designed to deal with most situations and requiring the least decisions from the user, and 3) manual override, which allows the photographer to set all of the controls.
