Tilt-shift photography

Tilt-shift photography refers to the use of camera movements on small- and medium format cameras, often tilting the lens relative to the image plane to achieve a very shallow depth of field. The technique relies on the Scheimpflug principle and usually requires the use of special lenses. “Tilt-shift” actually encompasses two different types of movements: rotation of the lens, called "tilt", and movement of the lens parallel to the image plane, called "shift".Tilt is used to control the orientation of the plane of focus (PoF), and hence the part of an image that appears sharp. Shift is used to control perspective, usually involving the convergence of parallel lines.

History and use

Movements have been available on view cameras since the early days of photography. Nikon introduced a lens providing shift movements for their 35 mm SLR cameras in the mid 1960s, [cite web | first = Haruo | last = Sato | title = Tale Seventeen : PC-Nikkor 28 mm f/4 | publisher = Nikon Corporation | url = http://imaging.nikon.com/products/imaging/technology/nikkor/n17_e.htm | accessdate=2008-07-10] and Canon introduced a lens that provided both tilt and shift movements in 1973; [ [http://www.canon.com/camera-museum/camera/lens/fd/data/17-35/ts_35_28_ssc.html Canon TS 35 mm f/2.8 SSC lens] . [http://www.canon.com/camera-museum/ Canon Camera Museum] . Retrieved on 2008-07-10.] many other manufacturers soon followed suit. Canon and Nikon each currently offer several lenses that provide both movements. Such lenses are frequently used in architectural photography to control perspective, and in landscape photography to get an entire scene sharp.

Some photographers have popularized the use of tilt for in applications such as portrait photography. The selective focus that can be achieved by tilting the plane of focus is often compelling because the effect is different from that to which many viewers have become accustomed. Walter Iooss Jr. of Sports Illustrated, Vincent Laforet, Ben Thomas, and many other photographers have images using this technique on their web sites.

Camera movements

Tilt

On a regular camera, the image plane (containing the film or image sensor), lens plane, and object plane are parallel, and objects in sharp focus are all at the same distance from the camera. When the lens plane is tilted relative to the image plane, the PoF is at an angle to the image plane, and objects at different distances from the camera can all be sharply focused if they lie on a straight line. With a tilted lens, the image plane, lens plane, and PoF intersect at a common line; [cite web | url=http://vsd.pennnet.com/Articles/Article_Display.cfm?Section=ARTCL&ARTICLE_ID=254651&VERSION_NUM=2&p=19 | title=Shift/tilt lenses bring new perspectives | publisher=Vision Systems Design | first=Andrew | last=Wilson | date=May 1 2006 | accessdate=2008-05-19 ] this behavior has become known as the Scheimpflug principle. When the PoF coincides with an essentially flat subject, the entire subject is sharp; in applications such as landscape photography, getting everything sharp is often the objective. But the PoF can also be oriented so that only a small part of it passes through the subject, producing a very shallow region of sharpness, and the effect is quite different from that obtained simply by using a large aperture with a regular camera.

View camera users usually distinguish between rotating the lens about a horizontal axis (tilt), and rotation about a vertical axis ("swing"); small- and medium-format camera users often refer to either rotation as “tilt”.

hift

In a subject plane parallel to the image plane, parallel lines in the subject remain parallel in the image. If the image plane is not parallel to the subject, as when pointing a camera up to photograph a tall building, parallel lines converge, and the result sometimes appears unnatural, such as a building that appears to be leaning backwards. Shift is a movement of the lens parallel to the image plane that allows the line of sight to be changed while keeping the image plane parallel to the subject; it can be used to photograph a tall building while keeping the sides of the building parallel. The lens can also be shifted in the opposite direction to accentuate the convergence for artistic effect.

Again, view camera users usually distinguish between vertical movements ("rise" and "fall") and lateral movements (shift or "cross"), while small- and medium-format users often refer to both types of movements as “shift”.

Applying camera movements

On a view camera, the lens and camera back are connected by a bellows, and many view cameras allow a considerable range of adjustment of both the lens and the camera back, so the tilt and shift movements are inherent in the camera. Applying tilt on a small- or medium-format camera usually requires a tilt-shift lens or perspective correction lens; shift can be applyed with the same type of lens or with a lens that offers only the shift movement.

Tilt-shift and perspective-correction lenses are available for many SLR cameras, but most are far more expensive than comparable lenses without movements. The Lensbaby SLR lens is a low-cost alternative for providing tilt and swing for many SLR cameras, although the effect is somewhat different from that of the lenses just described. Because of the simple optical design, aberrations are significant, and sharp focus is limited to a region near the lens axis. Consequently, the Lensbaby’s primary application is selective focus. If that is the objective, however, the Lensbaby may be a perfectly acceptable choice.

It is also possible to construct a tilt-shift lens of sorts, as described in the linked article by Dennison Bertram.

Uses of effect

By blurring, the viewer’s gaze may be directed away from parts of the image the photographer wishes to de-emphasize.

A smaller depth of field can be simulated by bringing the foreground and/or background out of focus.

Miniature faking

Miniature faking is a post-processing technique, which involves selectively blurring a photo to simulate the narrow depth of field found in macro photography and some tilt-shift photography, making the image appear to be of a miniature model. [cite web | url=http://www.slate.com/id/2159172/ | title=Can Photographers Be Plagiarists? | first=David | last=Segal | publisher=Slate | date=2007-02-07 | accessdate=2007-02-07 ]

ee also

* Camera movements
* Scheimpflug principle
*
* Tilt-shift lens

References

External links

* [http://hame.ca/tiltshift.htm A collection of links to galleries and information on tilt-shift photography]
* [http://www.boingboing.net/2006/01/27/photographer_takes_p.html Another collection of links to galleries and information on tilt-shift photography]
* [http://www.bentimagelab.com/sg/pages/Smallgantics.htm Tilt-shift photography on moving imagery]
* [http://www.creativepro.com/article/build-a-tilt-shift-camera-lens-peanuts Build a Tilt-Shift Camera Lens for Peanuts] — article by Czech fashion photographer Dennison Bertram
* [http://www.nytimes.com/packages/html/magazine/20070531_VINCENT_FEATURE/blocker.html A Really Big Show] -— tilt-shift slideshow of photos by Vincent Laforet with comentaries (requires Flash)
* [http://www.flickr.com/groups/tilt-shift-fakes/pool/ Tilt-shift photography on Flickr]
* [http://vnm.fi/~ttv/oldies/TS_Review/ MC ARAX 2.8/35mm Tilt & Shift lens Review]