They are used to take very high-quality photographs of static subjects on large film, or at high digital image resolution, and capable of much enlargement with good quality.
For some uses with long exposures, or flash lighting; a shutter is unnecessary; removing a lens cap to expose the film is sufficient.
Monorail cameras are among the simplest cameras possible according to their operating principles, consisting of the front standard (holding the lens) and rear standard (holding the ground glass viewing and focussing screen, then replaced by the film) sliding on a single rail, with a light-tight bellows stretched between.
They are built to a high standard of precision and smoothness of operation, and sell in low volume, which makes prices higher than most smaller cameras.
The body will be bought with lens panels and a film back; the owner will then choose lenses (in shutters) made by specialist manufacturers.
Several companies produce monorail camera bodies, including Arca-Swiss, Ebony, Horseman, Linhof, Cambo, Sinar, and Toyo.