Canon TS-E 17mm lens
Encyclopedia
The Canon
TS-E 17 mm 4L is a tilt-shift, ultra-wide-angle prime lens
that provides the equivalent of the corresponding view camera
front movements on Canon EOS
camera bodies. Unlike most other EF-mount
lenses, it does not provide autofocus
.
The TS-E 17 mm 4L provides four degrees of freedom
, allowing ±6.5° tilt with respect to the film or sensor plane and ±12 mm shift with respect to the center of the image area;
each movement can be rotated ±90° about the lens axis.
Shifting allows adjusting the position of the subject in the image area without moving the camera back; it is often used to avoid convergence of parallel lines, such as when photographing a tall building.
Tilting the lens relies on the Scheimpflug principle
to rotate the plane of focus away from parallel to the image plane; this can be used either to have all parts of an inclined subject sharply rendered, or to restrict sharpness to a small part of a scene. Tilting the lens results in a wedge-shaped depth of field
that may be a better fit to some scenes than the depth of field between two parallel planes that results without tilt.
Unlike most view cameras, the shift mechanism allows shifts along only one axis, and the tilt mechanism allows tilts about only one axis; however, the rotation of the mechanisms allows the orientations of the axes to be changed, providing, in effect, combined tilt and swing, and combined rise/fall and lateral shift. The TS-E 17 mm 4L uses the same barrel design as the TS-E 24 mm f/3.5L II, which allows the tilt and the shift mechanisms to be rotated independently of each other.
Canon Inc.
is a Japanese multinational corporation that specialises in the manufacture of imaging and optical products, including cameras, camcorders, photocopiers, steppers and computer printers. Its headquarters are located in Ōta, Tokyo, Japan.-Origins:...
TS-E 17 mm 4L is a tilt-shift, ultra-wide-angle prime lens
Prime lens
In film and photography, a prime lens is either a photographic lens whose focal length is fixed, as opposed to a zoom lens, or it is the primary lens in a combination lens system....
that provides the equivalent of the corresponding view camera
View camera
The view camera is a type of camera first developed in the era of the Daguerreotype and still in use today, though with many refinements. It comprises a flexible bellows which forms a light-tight seal between two adjustable standards, one of which holds a lens, and the other a viewfinder or a...
front movements on Canon EOS
Canon EOS
The Canon EOS autofocus 35 mm film and digital SLR camera system was introduced in 1987 with the Canon EOS 650 and is still in production as Canon's current DSLR system...
camera bodies. Unlike most other EF-mount
Canon EF lens mount
Introduced in 1987, the EF lens mount is the standard lens mount on the Canon EOS family of SLR film and digital cameras. EF stands for "Electro-Focus": automatic focusing on EF lenses is handled by a dedicated electric motor built into the lens...
lenses, it does not provide autofocus
Autofocus
An autofocus optical system uses a sensor, a control system and a motor to focus fully automatic or on a manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system has to be done manually until indication...
.
The TS-E 17 mm 4L provides four degrees of freedom
Degrees of freedom (engineering)
In mechanics, degrees of freedom are the set of independent displacements and/or rotations that specify completely the displaced or deformed position and orientation of the body or system...
, allowing ±6.5° tilt with respect to the film or sensor plane and ±12 mm shift with respect to the center of the image area;
each movement can be rotated ±90° about the lens axis.
Shifting allows adjusting the position of the subject in the image area without moving the camera back; it is often used to avoid convergence of parallel lines, such as when photographing a tall building.
Tilting the lens relies on the Scheimpflug principle
Scheimpflug principle
The Scheimpflug principle is a geometric rule that describes the orientation of the plane of focus of an optical system when the lens plane is not parallel to the image plane. It is commonly applied to the use of camera movements on a view camera...
to rotate the plane of focus away from parallel to the image plane; this can be used either to have all parts of an inclined subject sharply rendered, or to restrict sharpness to a small part of a scene. Tilting the lens results in a wedge-shaped depth of field
Depth of field
In optics, particularly as it relates to film and photography, depth of field is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image...
that may be a better fit to some scenes than the depth of field between two parallel planes that results without tilt.
Unlike most view cameras, the shift mechanism allows shifts along only one axis, and the tilt mechanism allows tilts about only one axis; however, the rotation of the mechanisms allows the orientations of the axes to be changed, providing, in effect, combined tilt and swing, and combined rise/fall and lateral shift. The TS-E 17 mm 4L uses the same barrel design as the TS-E 24 mm f/3.5L II, which allows the tilt and the shift mechanisms to be rotated independently of each other.
See also
- TS-E 24 mm
- TS-E 45 mm
- TS-E 90 mm