A beautiful tilt/shift lens priced as high as Nikon could get away with.
What is a tilt/shift lens?
A lens with mechanical bending and shearing movements in the barrel. The bending of the lens rotates the plane of focus following a complex principle (see: Scheimpflug Principle), allowing you to accurately focus (or creatively mis-focus) using a plane that isn’t parallel to the film/sensor. The shearing movement offsets the lens from the center of the lens mount, allowing you to photograph objects at an angle while keeping the camera flat and level, preserving the more attractive level perspective.
A tilt/shift lens restores some of the capabilities that SLRs lost when they split off from view cameras half a century ago. View cameras can tilt and shift by design, as can some rangefinders. For a hundred years tilt and shift were essential variables of photography; focus was the combination of three variables, not one.
Hence the purpose of a tilt/shift lens is to focus correctly when a traditional lens would not.
What is it used for and by whom?
Primarily nature, architectural and commercial product photography. These are the photographic subjects that either are the most at odds with a fixed vertical plane of focus, or that require extremely precise focus or perspective control. More recently they’ve become popular for portraiture, and miscellaneous creative works, pulitzer-winner Vincent Laforet used them to shoot sports for example.
Today they are used almost exclusively by professionals and well-fed photo artists. They haven’t really penetrated the mindshare of advanced amateurs, and they’ll probably never appeal to the wider public who would probably regard them as too hard to use. Mostly I suspect that they haven’t entered the consciousness of many more amateur photographers because they’re priced so horribly out of reach.
Some amateur photographers feel as I do however, that they are an essential tool in your bag!
An ugly expensive tilt/shift lens that doesn’t perform very well, the best kind, made by Canon.
Who makes tilt/shift lenses?
Mainly Canon (>$1K), Nikon (<$2K), and Zeiss/Hartblei (~$6K). There is an unknown company in Ukraine that ships a 35mm TS lens anywhere in the world, Arax ($700), and Novoflex will sell you bellows that offer a similar effect if you don’t like wide angles too much.