Tilted plane focus
Encyclopedia
"Tilted plane photography" is a method of employing focus as a descriptive, narrative or symbolic artistic device. It is distinct from the more simple uses of selective focus which highlight or emphasise a single point in an image, create an atmospheric bokeh
, or miniaturise an obliquely-viewed landscape. In this method the photographer is consciously using the camera to focus on several points in the image at once while de-focussing others, thus making conceptual connections between these points.
is relative to spatial depth. Selective focus in photography is usually associated with depth of field. A pinhole camera
generates an image of infinite relative focus, from a point just outside the camera opening out to infinity
. Lenses
focus more selectively so that, for objects near the lens, the distance between lens and sensor or film is increased and is shortened for more distant objects, to a point beyond which all is in focus. In telephoto lenses this point may be tens or hundreds of metres from the camera. Wide-angle lens
es distinguish differences in depth only up to a short distance, beyond which all is in focus.
is an effect that permits bringing objects into focus at varying distances from the camera, and at varying depth between each other, into the field of view. A short lens, as explained above, will bring objects into focus that are relatively close to the camera, but it will also keep focus at greater distances between objects. A telephoto lens will be very shallow in its gamut of focus.
Reducing the size of the aperture of the lens deepens the focus. At a pinhole size this will increase in effect, though the closer the objects are to the camera, the shorter the distance between focussed objects.
This technique is based on the principle of Scheimpflug
which, traditionally, is combined with small aperture to increase the gamut of focus beyond that achievable by depth of field alone. Usually no out-of-focus artifacts are desired in the image resulting from Scheimpflug adjustments. Here the converse is true. With the lens at full aperture, the photographer selects points in depth in the scene on which to focus and throws other points out-of-focus. This increases the contrast between the sharp and blurred areas and the selected application of focus and blur remains apparent to the viewer.
permits full, incrementally calibrated control over this technique, though it is possible to achieve with other cameras and formats. It is possible to achieve similar effects on a 35mm camera
or digital single-lens reflex camera (DSLR). The lens (preferably a long lens of around 80mm) of a manual single-lens reflex camera
(SLR) is set to infinity and shutter speed is set for the correct exposure at the widest aperture. Then the lens is removed and held against the lens mount opening and tilted. It is possible to see the tilted plane effect through the viewfinder. Despite the fact that the lens is separated from the camera body, there is little flare or fogging, and this can be avoided by placing a foam rubber 'donut' between the lens and camera body. Using a lens made for a medium-format camera will provide wider coverage, and therefore more scope for tilting the lens still further off-axis, with a capacity to focus closer and less likelihood of flare and light leaks, as the back of the lens will in most cases be larger than the lens mount.
A commercial option is the Lensbaby
, although it does not permit the same degree of manipulation of the lens to off-axis positions or tilts required for the technique. A better but more expensive option is to use tilt/shift lenses (e.g. Canon 24mm TS-E).
was a strong advocate of this use of selective focus. For example in "Prayer and Praise", produced in 1865, there is a deliberate placement of focus at more than three points: on the face and parts of the body of the foreground child; and faces of mother and father; while a second child's face is thrown radically out of focus.
Bokeh
In photography, bokeh is the blur, or the aesthetic quality of the blur, in out-of-focus areas of an image, or "the way the lens renders out-of-focus points of light."...
, or miniaturise an obliquely-viewed landscape. In this method the photographer is consciously using the camera to focus on several points in the image at once while de-focussing others, thus making conceptual connections between these points.
Limits to focus in imaging
FocusFocus (optics)
In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...
is relative to spatial depth. Selective focus in photography is usually associated with depth of field. A pinhole camera
Pinhole camera
A pinhole camera is a simple camera without a lens and with a single small aperture – effectively a light-proof box with a small hole in one side. Light from a scene passes through this single point and projects an inverted image on the opposite side of the box...
generates an image of infinite relative focus, from a point just outside the camera opening out to infinity
Infinity
Infinity is a concept in many fields, most predominantly mathematics and physics, that refers to a quantity without bound or end. People have developed various ideas throughout history about the nature of infinity...
. Lenses
Photographic lens
A camera lens is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.While in principle a simple convex lens will suffice, in...
focus more selectively so that, for objects near the lens, the distance between lens and sensor or film is increased and is shortened for more distant objects, to a point beyond which all is in focus. In telephoto lenses this point may be tens or hundreds of metres from the camera. Wide-angle lens
Wide-angle lens
From a design perspective, a wide angle lens is one that projects a substantially larger image circle than would be typical for a standard design lens of the same focal length; this enables either large tilt & shift movements with a view camera, or lenses with wide fields of view.More informally,...
es distinguish differences in depth only up to a short distance, beyond which all is in focus.
Depth of field
Depth of fieldDepth 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...
is an effect that permits bringing objects into focus at varying distances from the camera, and at varying depth between each other, into the field of view. A short lens, as explained above, will bring objects into focus that are relatively close to the camera, but it will also keep focus at greater distances between objects. A telephoto lens will be very shallow in its gamut of focus.
Reducing the size of the aperture of the lens deepens the focus. At a pinhole size this will increase in effect, though the closer the objects are to the camera, the shorter the distance between focussed objects.
Plane of focus
Because focus depends on the distance between lens and the sensor or film plane, focus in the space in front of the camera is not on a point but rather on a plane parallel to the film plane. Spherical construction of lenses, rather than the ideal parabolic construction which is rarely and expensively achieved, means that this plane is slightly concave—more so in simple single element lenses and increasingly so with lenses of lower quality construction and materials. Compound lenses are built to correct this "spherical aberration" or "curvature of field".Tilting the plane of focus
Varying the distance between the lens and sensor or film plane across the field of view permits focussing on objects at varying distances from the camera. One means of achieving this is to tilt the lens and/or the sensor or film plane in relation to each other. This will mean that individual points in the picture plane will focus on different points of depth, with the effect that the plane of sharp focus will tilt.This technique is based on the principle of Scheimpflug
Scheimpflug
-The surname Scheimpflug:*Lotte Scheimpflug - luger*Theodor Scheimpflug - Austrian photographer...
which, traditionally, is combined with small aperture to increase the gamut of focus beyond that achievable by depth of field alone. Usually no out-of-focus artifacts are desired in the image resulting from Scheimpflug adjustments. Here the converse is true. With the lens at full aperture, the photographer selects points in depth in the scene on which to focus and throws other points out-of-focus. This increases the contrast between the sharp and blurred areas and the selected application of focus and blur remains apparent to the viewer.
Tilted plane focus on smaller formats
A view cameraView 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...
permits full, incrementally calibrated control over this technique, though it is possible to achieve with other cameras and formats. It is possible to achieve similar effects on a 35mm camera
135 film
The term 135 was introduced by Kodak in 1934 as a designation for cartridge film wide, specifically for still photography. It quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film format...
or digital single-lens reflex camera (DSLR). The lens (preferably a long lens of around 80mm) of a manual single-lens reflex camera
Single-lens reflex camera
A single-lens reflex camera is a camera that typically uses a semi-automatic moving mirror system that permits the photographer to see exactly what will be captured by the film or digital imaging system, as opposed to pre-SLR cameras where the view through the viewfinder could be significantly...
(SLR) is set to infinity and shutter speed is set for the correct exposure at the widest aperture. Then the lens is removed and held against the lens mount opening and tilted. It is possible to see the tilted plane effect through the viewfinder. Despite the fact that the lens is separated from the camera body, there is little flare or fogging, and this can be avoided by placing a foam rubber 'donut' between the lens and camera body. Using a lens made for a medium-format camera will provide wider coverage, and therefore more scope for tilting the lens still further off-axis, with a capacity to focus closer and less likelihood of flare and light leaks, as the back of the lens will in most cases be larger than the lens mount.
A commercial option is the Lensbaby
Lensbaby
Lensbaby is a line of camera lenses for SLR cameras that combine a simple lens with a bellows or ball and socket mechanism for use in special-effect photography. A lensbaby can give effects normally associated with view cameras...
, although it does not permit the same degree of manipulation of the lens to off-axis positions or tilts required for the technique. A better but more expensive option is to use tilt/shift lenses (e.g. Canon 24mm TS-E).
History
Julia Margaret CameronJulia Margaret Cameron
Julia Margaret Cameron was a British photographer. She became known for her portraits of celebrities of the time, and for photographs with Arthurian and other legendary themes....
was a strong advocate of this use of selective focus. For example in "Prayer and Praise", produced in 1865, there is a deliberate placement of focus at more than three points: on the face and parts of the body of the foreground child; and faces of mother and father; while a second child's face is thrown radically out of focus.
See also
- Angle of viewAngle of viewIn photography, angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view....
- BokehBokehIn photography, bokeh is the blur, or the aesthetic quality of the blur, in out-of-focus areas of an image, or "the way the lens renders out-of-focus points of light."...
- Circle of confusionCircle of confusionIn optics, a circle of confusion is an optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a point source...
- Deep focusDeep focusDeep focus is a photographic and cinematographic technique using a large depth of field. Depth of field is the front-to-back range of focus in an image — that is, how much of it appears sharp and clear. Consequently, in deep focus the foreground, middle-ground and background are all in focus...
- Depth of fieldDepth of fieldIn 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...
- Depth-of-field adapterDepth-of-field adapterA depth-of-field adapter is used to achieve shallow depth of field on a video camera whose fixed lens or interchangeable lens selection is limited or economically prohibitive at providing such effect...
- Depth of focusDepth of focusDepth of focus is a lens optics concept that measures the tolerance of placement of the image plane in relation to the lens...
- Focus (optics)Focus (optics)In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...
- Frazier lensFrazier lensThe Frazier lens is a special camera lens designed by photographer Jim Frazier. The Frazier lens provides a massive depth of field, allowing the foreground and background of an image to be in focus. Frazier's lenses have been widely used in Hollywood and wildlife cinematography...
(very deep DOF) - Hyperfocal distanceHyperfocal distanceIn optics and photography, hyperfocal distance is a distance beyond which all objects can be brought into an "acceptable" focus. There are two commonly used definitions of hyperfocal distance, leading to values that differ only slightly:...
- Miniature faking
- Perspective distortionPerspective distortion (photography)In photography and cinematography, perspective distortion is a warping or transformation of an object and its surrounding area that differs significantly from what the object would look like with a normal focal length, due to the relative scale of nearby and distant features...
- Shallow focusShallow focusShallow focus is a photographic and cinematographic technique incorporating a small depth of field. In shallow focus one plane of the image is in focus while the rest is out of focus. Shallow focus is typically used to emphasize one part of the image over another...
- Tilt-shift photographyTilt-shift photography"Tilt-shift photography" refers to the use of camera movements on small- and medium-format cameras, and sometimes specifically refers to the use of tilt for selective focus, often for simulating a miniature scene...
- View cameraView cameraThe 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...