View camera
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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 composed 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.
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[edit] View camera operation
To operate the view camera, the photographer opens the shutter on the lens to focus and compose the image on a ground glass plate on the rear standard. The ground glass is held in the same plane that the film will later occupy, so that an image that is well focussed on the ground glass will be well focussed on the film. The ground glass image is somewhat dim and can be difficult to view in bright light. The photographer will often use a "dark cloth" over his or her head, and the rear of the camera. The darkcloth shrouds the viewing area and keeps environmental light from obscuring the image. In the dark space created by the dark cloth, the image appears as bright as it can and allows the image to be most easily viewed, assisting in focussing and composition.
Often a photographer will use a magnifying lens, usually a high quality loupe, to critically focus the image. An addition over the ground glass called a Fresnel lens can considerably brighten the ground glass image (albeit with a slight loss of focusing accuracy). The taking lens may be stopped down to help gauge depth of field effects and vignetting, but while the image is being composed the lens is generally opened to its widest setting to aid in focussing.
The ground glass and ground glass frame assembly, known as the spring back, is held in place by springs that pull and hold the ground glass firmly into the plane of focus during the focussing and composing process. Once the focussing process is complete, the same springs act as a flexible clamping mechanism to press the film holder into the same plane of focus the ground glass occupied.
To take the photograph the ground glass is pulled back and the film holder is slid into its place. The spring back keeps the film holder firmly in place.
The shutter is then closed and cocked, the shutter speed and aperture set, and the darkslide of the film holder removed, revealing the sheet of film. The shutter is then triggered, the exposure made, and the darkslide replaced into the film holder.
Sheet film holders are generally interchangeable between the various brands and models of view camera, in the most common formats, adhering to a set of standards. The largest cameras and more uncommon formats are less standardized.
There are special film holders and accessories that fit in place of a standard film holder, such as Grafmatic, which could fit six sheets of film in the space of an ordinary two-sheet holder, and some light meters have an attachment that inserts into the film holder slot on the camera back that allows the photographer to measure light falling at a specific point on the film plane. The entire film holder/back assembly is often an industry standard Graflex back, removable so accessories like roll-film holders and digital imagers can be used without altering focus.
[edit] Types of view camera
Generally, view cameras are built for sheet film, one exposure for each sheet. These can be quite large, and are typically standardized to the following large film formats (measurements in inches): 4x5, 5x7, 4x10, 5x12, 8x10, 11x14, 7x17, 8x20, 12x20, 20x24, and 30x40. In Europe and Asia, the long side is often listed first when discussing sheet film size and the associated view camera equipment, albeit in inches rather than a metric measurement, ie. a 5x4 camera is identical to a 4x5 camera. Sometimes the closest equivalent in centimeters is used as well, ie. 9x12 or 12x9 for 4x5.
Far and away the most popular formats are 4x5 and 8x10, with the majority of cameras and lenses designed for one or the other.
There are several varieties of view camera, engineered for different purposes and allowing different degrees of movement and portability. They include:
- Monorail Camera - This is the most common type of studio view camera, with the front and rear standards being mounted to a single rail that is fixed to a camera support. This design allows the greatest range of movements and flexibility, with both front and rear standards able to tilt, shift, rise, fall and swing in similar proportion. These are generally made of metal with leather or synthetic bellows, and are difficult to pack for travel. Sinar and Toyo are popular manufacturers of monorail view camera systems. ARCA-Swiss produces monorail cameras for field use in addition to models for the more conventional studio applications. Many manufacturers also offer monorail extensions, which permit the front or rear standards to move further away from each other, allowing for focus on very close objects (macrophotography).
- Field Camera - These have the front and rear standard mounted to sliding rails on a flat bed that is fixed to a camera support. These cameras are designed to fold up into a small box for portability, and can be made of wood as well as composites like carbon fiber. The trade off is that the standards are not as mobile or as adjustable as with a monorail design, especially the rear standard, which may even be fixed and offer no movement. Their light weight and ease of packing and set-up are popular with landscape photographers. Extremely large cameras of this type, using 11x14 film and larger, or panoramic film sizes such as 4x10 or 8x20, are sometimes referred to as Banquet Cameras. Such cameras were once used to photograph large, posed groups of people to mark an occasion, such as those attending a banquet. Studio and Salon Cameras are similar in construction, but do not fold up for portability. Wisner and Tachihara are popular examples of modern Field Cameras at either end of the price spectrum.
- Press and Technical Cameras - These are very portable, but often have the least amount of usable movement of the three main types of view camera. Originally made for news photographers before roll film became popular, they are designed to fold up, with the lensboard in place, in less than a second. Some are equipped with rangefinders and viewfinders for hand-held work. The most recent have a central shutter with flash synchronization, some antique models have only a focal plane shutters. Many have two shutters, allowing fast shutter speeds and the use of non-shuttered lenses with the focal plane shutter and electronic flash synchronization at any speed with in-lens the central shutter. These are typically made of machined and stamped metal, designed for daily use by working newsmen, so they are usually very robust, but also very heavy. The Speed Graphic in its many incarnations was the camera of choice for the American photojournalist in the Golden Age of Hollywood and in the Second World War, and used examples are still popular with photography students. Modern examples of Technical and Press View Cameras are still in production by Horseman, Wista and Linhof.
[edit] 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.
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.
Some limited view camera-type movements are possible with SLR cameras using various perspective control lenses.
[edit] 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.
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 than 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.
To correct 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 cameras, 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.
[edit] 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 affects 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.
[edit] 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.
This effect is often incorrectly thought of as increasing the depth of field. Depth of field is a function of the focal length, aperture, and image distance. As long the photographer wants sharpness in a plane that is parallel to the film, tilt is of no use. However, tilt has a strong effect on the depth of field by drastically altering its shape, making it asymmetrical. Without tilt, the limits of near and far acceptable focus are parallel to the plane of sharp focus as well as parallel to the film. With forward tilt, the plane of sharp focus tilts even more and the near and far limits of acceptable focus form a wedge shape (viewed from the side). Thus, the lens still sees a cone shaped portion of whatever is in front of it while the wedge of acceptable focus is now more closely aligned with this cone. Therefore, depending on the shape of the subject, a wider aperture can be used, lessening concerns about camera stability due to slow shutter speed and diffraction due to too-small aperture.
Group f/64, the loose association of “West Coast” photographers such as Ansel Adams and Imogen Cunningham, must have selected their name with a certain amount of hyperbole in mind. They were not specifying that aperture as a silver bullet.
The purpose of tilting is to achieve the desired depth of field using the optimal possible aperture. Using a needlessly small aperture risks losing to diffraction and camera or subject motion what one gains from depth of field. Only testing a given scene, or experience, will show whether tilting is better than leaving the standards neutral and relying on the aperture alone to achieve the desired depth of field. If the scene is sharp enough at f/32 with 2 degrees of tilt but would need f/64 with zero tilt, then tilt is the solution. If another scene would need f/45 with or without tilt, then nothing is gained.
With a forward tilt, the shape of the portion of a scene in acceptable focus is a wedge. Thus, the scene most likely to benefit from tilting is short in the front and expands to a greater height or thickness toward the horizon. A scene consisting of tall trees in the near, middle and far distance may not lend itself to tilting unless the photographer is willing to sacrifice either the top of the near trees and/or the bottom of the far trees.
Assuming lens axis front tilt, here are the trade offs in choosing between a small degree of tilt (say less than 3) and a larger tilt: A small tilt causes a wider or fatter wedge but one that is far off axis from the cone of light seen by the lens. Conversely, a large tilt (say 10 degrees) causes the wedge to be more aligned with the view of the lens but with a narrower wedge. Thus, a modest tilt is often, or even usually, the best starting point. See Focusing the View Camera by Harold Merklinger.
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.
[edit] 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.
[edit] 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 manner 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.
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.
[edit] View camera lenses
A view camera lens typically consists of:
- A front lens element, sometimes referred to as a cell.
- A shutter, which consists of an electronic or spring-actuated iris which controls exposure duration. (On early lenses, air-actuated shutters were sometimes used, and others had no moving shutter at all, a simple lens cap was used instead.)
- The aperture diaphragm
- A lensboard
- A rear lens element (or cell).
Almost any lens of the appropriate coverage area may be used with almost any view camera. All that is required is that the lens be mounted on a lensboard compatible with the camera. A lensboard is simply a flat board, typically square in shape and made of either metal or wood, designed to lock securely into the front standard of a particular view camera, typically engineered for quick removal and replacement for swapping lenses in the field. Not all lensboards work with all models of view camera, though some cameras may be designed to work with a common lensboard type. Lensboards usually come with a hole sized according to the shutter size, often called the Copal Number. Copal is the most popular maker of leaf shutters for view camera lenses. The following is a list of the Copal Number and the corresponding diameter required in the lensboard to mount the shutter:
- Copal #0 - 34.6 mm
- Copal #1 - 41.6 mm
- Copal #3 - 65 mm
- Copal #3s - 64.5 mm
The lens is designed to split into two pieces, the front and rear elements mounting to the shutter and lensboard. This is usually done by a trained technician, but mechanically inclined photographers often do this themselves.
View camera lenses are designed with both focal length and coverage in mind - a 300mm lens may give a different angle of view (either over 31° or over 57°) depending on whether it was designed to cover a 4x5 or 8x10 image area. Most lenses are designed to cover more than just the image area to allow for "movement" - positioning the front or rear standards out of linear alignment for perspective and focussing closer than infinity without vignetting.
Focusing involves moving the front standard closer to or further away from the rear standard, the lens itself does not have nor need any internal helical focusing device. The lens elements do not need to move in relation to one another.
Very long focus lenses or very short wide-angle lenses may require the camera be fitted with special bellows to bring the subject into proper focus, as the regular bellows will be either unable to extend far enough to accommodate long lenses, or collapse tight enough for extremely short ones. "Bag bellows" are common wide-angle photography accessories, replacing the accordion-folded bellows with a simple light-tight leather or synthetic bag. Recessed lensboards are also sometimes used to get the rear element of a wide angle lens close enough to the film plane to achieve focus. Some cameras offer extra-long rails and bellows to mount the standards to for long lens work.
Zoom lenses are unheard of in view camera photography, but there are "convertible" lenses that allow the photographer to add and remove lens elements in the field to alter the optical formula, resulting in a new focal length. These are popular with field photographers who would prefer to save weight by carrying one convertible lens rather than two or three regular lenses. The trade off is a smaller maximum aperture than is usual with regular lenses, and sometimes convertible lenses are not corrected for chromatic aberration, making them useless with color film.
Soft focus lenses introduce spherical aberration deliberately into the optical formula for a pleasing ethereal effect. The amount of soft-focus effect is determined by either aperture size or special disks that fit into the lens to modify the aperture shape. Some antique lenses have a lever which controls the softening effect by altering the optical formula on the fly, similar to modern SLR soft focus lenses.
Current large format lens manufacturers:
- Schneider Kreuznach - Price-no-object high quality lenses.
- Nikon - Noted for its high quality telephoto designs. As of January 2006, Nikon announced it would discontinue manufacturing its LF lenses.
- Rodenstock - Extremely high quality, reasonably priced.
- Fujinon - Has a strong presence in Asia.
- Cooke - Interesting and expensive soft focus and color-corrected convertible lenses.
- Congo - Budget lenses, but offering interesting soft focus and telephoto designs.
- Seagull/Shen-Hao/Sinotar - Budget lenses.
- Wisner - Offer a modern convertible Plasmat set.
- Sinar - Rebranded Rodenstock lenses.
- Caltar - Rebranded Rodenstock lenses.
- Linhof - Rebranded Rodenstock and Schneider lenses.
[edit] View Camera Film
View cameras use sheet film but can use roll film (generally 120 size) by using special roll film holders. Popular image formats for the 4x5 camera are 6x6, 6x7, 6x9, 6x12, and 6x17cm. 6x12 and 6x17cm are suited to panoramic photography.
Without modifying the camera (but with an inexpensive modification of the darkslide), a photographer can expose a half sheet of film at a time. While this could be useful for saving money, it's almost always instead a means of changing the format so that, for example, a 4x5 camera can take two 2x5 panoramic photos, an 8x10 can take two 4x10s etc. This is popular for landscape imagery, and in the past was common at banquets and similar functions.
[edit] Advantages and Disadvantages
[edit] Advantages
- Large film format allows a very detailed picture and for enlargement with less "grain" or loss of quality. It also allows for contact printing at easily viewable sizes without use of an enlarged negative—the preferred method for alternative process printing.
- The larger film sizes used in view cameras allows photographs made with them to exhibit more discrete steps in the tonal range from black to white allowing for smoother surface tonality on objects represented in finished prints.
- Elimination of converging lines when the camera is angled and looking at parallel lines. As an example, if one were to take a camera sitting on the ground, and point it up at a tall building, the parallel lines of the building would converge at a point. By realigning the front and rear standards of a view camera to be perpendicular to the ground, this phenomenon is eliminated. This is useful in architecture photography.
- The ability to place the plane of sharp focus. In a 'normal' camera the lens and film planes are always parallel to one another. By use of the Scheimpflug principle and the Hinge rule, the camera operator is able to place the plane of sharp focus, thus achieving an image with all the chosen elements in focus. Either standard can be manipulated (tilted through the horizontal, or swung through the vertical) to achieve this effect. It must be noted that such movements on the rear standard will also affect the perspective of the image.
- The camera operator is forced to think about the proposed shot. The weight of the camera (and associated equipment such as lenses, tripod, film holders etc) does not lead to simple 'snap' shots. Having said that, many of the famous press images of the 30s and 40s were produced with hand-held 5x4 format cameras.
- Lenses generally have leaf shutters that will synchronize with flash at all speeds although most lenses have a maximum shutter speed of 1/500 second.
[edit] Disadvantages
- Lack of automation: most view cameras are fully manual. Consequently, novice users and even veterans are prone to making numerous mistakes throughout the process. Sinar cameras go some way to making the process less time-consuming, with self-cocking shutters and film-plane metering.
- Size and weight: the old adage "View camera photographers have strong backs and weak minds" may raise a smile from some practitioners.
- Time to set up and compose: not exactly optimal for that image that isn't going to hang around, though Paul Caponigro did get very lucky with his "Running White Deer".
- Cost: view cameras are often hand-built and made with limited production runs which tends to push up the cost when compared to other, mass-produced, camera types. Sheet film is also quite expensive compared to roll film.
- The long focal length lenses required for view cameras, especially for large format film sizes, are slow and have shallow depth of field compared to smaller format cameras.
Some of these disadvantages can be turned into advantages. For example, set-up and composure time can tend to cause the photographer to slow down, thus, forcing him to visualize the image beforehand. Because view cameras are rather difficult to set up and focus, the photographer must scout the location for the best vantage point, perspective, etc. before snapping the shutter. One of the most important tips often given to beginning 35mm photographers is for them to use a tripod for the specific reason that a tripod will slow down the process. This is especially true for the view camera user.
