Fixed focus can be a less expensive alternative to autofocus, which requires electronics, moving parts, and power. Since fixed-focus lenses require no input from the operator, they are suitable for use in cameras designed to be inexpensive, or to operate without electrical power as in disposable cameras, or in low-end 35 mm film point and shoot cameras, or in cameras featuring simple operation. These are usually wide-angle lenses with fixed aperture, and cameras with these lenses generally use a viewfinder for composition.