View camera

The view camera is a type of camera with a very long history (some modern examples are often mistaken for antiques), but they are still used today by professional and amateur photographers who want full control of their images. The view camera is basically a light-tight assembly comprised of a flexible mid-section, or bellows, attached to a device that holds a film sheet, photo plate or digital imager at one end (the rear standard) and a similar one that holds the lens at the other end (the front standard). The front and rear standards are not fixed relative to each other (unlike most cameras). Movement of the front and rear standards allows the photographer to move the lens and film plane independently for precise control of the image's focus, depth of field and perspective.

View camera movements

Photographers use view cameras to control focus and convergence of parallel lines. Image control is done by moving the front and/or rear standards. Movements are the ways the front and rear standards can be positioned to alter perspective and focus. The term can also refer to the mechanisms on the standards that allow the position to be achieved.

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Not all cameras have all movements available to both the front and rear standards, and some cameras have more movements available than others. In addition, some cameras are designed with mechanisms that make intricate movement combinations easier for the photographer to accomplish.

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Rise and Fall

Rise and fall are the movements of either the front or rear standard vertically along a line in a plane parallel to the film plane. Rise is a very important movement especially in architectural photography. Generally, the lens is moved vertically?either up or down?along the lens plane in order to change the portion of the image that will be captured on the film.

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The main effect of rise is to eliminate the optical illusion that tall buildings are ?falling over backwards.? One way to get the image of a tall building to appear on the film is to point the camera upwards. This causes the top of the building to be optically further away that the bottom of the building. Objects further away tend to appear smaller than do objects that are near by. This phenomenon is called convergence. If we assume the two sides of the building are parallel to each other, then, like railroad tracks, the sides of the building will converge at the top. This effect is captured on film to give the appearance that the top of the building is smaller than the bottom of the building. The building will appear on film as though it were tipping over backwards.

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To correct for the convergence of parallel lines, the film plane must be kept parallel to the face of the building. This usually means the film plane is vertical. Unless the camera has a wide angle lens attached, some of the building will not be captured on film. Of course, the use of a wide angle lens is one way to keep the film plane vertical and still capture the entire height of the building but a lot of foreground will also be captured. Another method, the one available on large format camera?s, is to raise the lens. Generally, the lens produces a larger image circle than the film can record. This is especially true of most large format lenses. By moving the lens up, the image is effectively moved down such that the top of the building can be captured on the film. In Figure a) below, the lens is in the ?normal? position. Notice how much of the image is wasted. In Figure b), the lens has been shifted up. The top of the building, at the sacrifice of the green ground, is now inside the area captured on film.

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Shift

Moving the standard left or right in relation to the film plane is called lens shift or simply shift. This movement is similar to the rise and fall movements but effect the image in the horizontal axis instead of the vertical axis. A possible use for shift is to remove the image of the camera from the final image when photographing directly into a mirrored surface.

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Tilt

Altering the angle of the lens in relation to the film plane by tilting the lens standard back and forth is called lens tilt or just tilt. Tilt is another important movement and is especially useful in Landscape Photography. By using the Scheimpflug principle, the ?plane of sharp focus? can be changed so that any plane can be brought into sharp focus. When the film plane and lens plane are parallel as is the case for most 35mm cameras, the plane of sharp focus will also be parallel to these two planes. If, however, the lens plane is tilted with respect to the film plane, the plane of sharp focus will also be tilted according to geometrical and optical properties. The three planes will intersect in a line below the camera for downward lens tilt. The tilted plane of sharp focus is very useful in that this plane can be made to coincide with a near and far object. Thus, both near and far objects on the plane will be in focus.

Related Topics:
Landscape Photography - Scheimpflug principle

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This effect is often incorrectly thought of as increasing the depth of field. Depth of field is a function of the lens, aperture, and image distance. Tilt has no effect on the depth of field. Depth of field for a tilted plane of sharp focus will occur on either side of the plane. For example, if the plane of sharp focus runs through the middle of a distant tree, the center of the tree will be in sharp focus. The tree will be increasingly more out of focus as distance from the center is increased. Thus, small apertures are still required to ensure the entire tree will be in acceptable focus.

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Small and medium format cameras have fixed bodies that do not allow for misalignment of the film and lens planes, intentionally or not. Tilt and shift lenses can be purchased from a number of lens makers that allow these cameras to have a small amount of adjustment, mostly rise and fall. High quality tilt/shift lenses are quite expensive. For the price of a new Nikon tilt/shift lens, one can purchase a good quality used large format camera that offers much more range of adjustment.

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Swing

Altering the angle of the lens standard in relation to the film plane by swiveling it from side to side is called swing. Swing is similar to Tilt but in the horizontal axis. Swing may be used to achieve sharp focus along the entire length of a picket fence, for example.

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Back Tilt/Swing

Angular movements of the rear standard change the angle between the lens plane and the film plane just as front standard angular movements do. Although rear standard tilt will change the plane of sharp focus in the same manor as front standard tilt does, this is not usually the reason rear tilt/swing is used. When a lens is a certain distance (its focal length) away from the film, distant objects such as faraway mountains are in focus. Moving the lens farther from the film brings closer objects into focus. Tilting or swinging the film plane puts one side of the film farther from the lens than the center is and the opposite point of the film is therefore closer to the lens.

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One reason to swing or tilt the rear standard is to keep the film plane parallel to the face of the object being photographed. Another reason to swing or tilt the rear standard is to control convergence and, hence, perspective. By swinging the rear standard, perspective can be changed by making more distant objects appear closer, for example.

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