Scanography
Encyclopedia
Scanography, also spelled scannography more commonly referred to as scanner photography, is the process of capturing digitized images of objects for the purpose of creating printable art
Art
Art is the product or process of deliberately arranging items in a way that influences and affects one or more of the senses, emotions, and intellect....

 using a flatbed "photo" scanner with a CCD (charge-coupled device)
Charge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...

 array capturing device. The term scanography formerly referred to medical scanning, but is unrelated in either purpose or technique. Fine art scanography differs from traditional document scanning by using atypical objects, often three dimensional, as well as from photography, due to the nature of the scanner's operation.

History of scanography

The process of creating art with a scanner can be as simple as arranging objects on the scanner and capturing the resulting image; in fact, some early artists in the field worked with photocopier
Photocopier
A photocopier is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat...

s to capture and print in a single step, resulting in the field of Xerox art
Xerox art
Xerox art is created by putting objects on the glass, or image area, of a copying machine and by pressing "start" to making an image. If the object is not flat, or the cover does not totally cover the object, the image is distorted in some way...

. Artist Sonia Landy Sheridan, artist in residence at 3M
3M
3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....

 and founder of the Generative Systems program at the Art Institute of Chicago
Art Institute of Chicago
The School of the Art Institute of Chicago is one of America's largest accredited independent schools of art and design, located in the Loop in Chicago, Illinois. It is associated with the museum of the same name, and "The Art Institute of Chicago" or "Chicago Art Institute" often refers to either...

 was one of the first to exploit this ability in 1968, altering the variables of the photocopying process to produce artwork rather than mere copies. Though the physical process of arranging objects on a glass platen to capture a photogram is shared by both "Xerox" artists and "scanographers", regarding image quality- scanner photography has more in common with large format photography. The process records extremely fine detail with a rather shallow depth of field and produces a digital file (or "digital negative") for printmaking.

Using a computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

 and a photo editor between the scanning and the printing process provides the artist with a greater level of control, allowing, at a minimum, the ability to "clean" the image by removing specks and other imperfections in the capture.
With the increased availability and affordability of flatbed color scanners in the 1990s, photoartists could now purchase a scanner rather than rent this equipment and the technician necessary to operate it, as Darryl Curran did in the early 1990s. Renting studio time at Nash Editions, Curran captured "scannograms" of objects from 1993-97. His iris prints where exhibited February 1997 at Texas Woman's University. Harold Feinstein's One Hundred Shell and One Hundred Flower series contained scanned images side by side with traditional large format photography. Joseph Scheer scanned moths in Night Visions: The Secret Designs of Moths. A 2008 exhibition titled "Scanner as Camera" at Washington and Lee University
Washington and Lee University
Washington and Lee University is a private liberal arts college in Lexington, Virginia, United States.The classical school from which Washington and Lee descended was established in 1749 as Augusta Academy, about north of its present location. In 1776 it was renamed Liberty Hall in a burst of...

 in Lexington, Virginia
Lexington, Virginia
Lexington is an independent city within the confines of Rockbridge County in the Commonwealth of Virginia. The population was 7,042 in 2010. Lexington is about 55 minutes east of the West Virginia border and is about 50 miles north of Roanoke, Virginia. It was first settled in 1777.It is home to...

 drew eight artists from across the United States whose subjects ranged from scanned and digitally manipulated historic ambrotype
Ambrotype
right|thumb|Many ambrotypes were made by unknown photographers, such as this American example of a small girl holding a flower, circa 1860. Because of their fragility ambrotypes were held in folding cases much like those used for [[daguerreotype]]s...

 and tintype
Tintype
Tintype, also melainotype and ferrotype, is a photograph made by creating a direct positive on a sheet of iron metal that is blackened by painting, lacquering or enamelling and is used as a support for a collodion photographic emulsion....

 photographs and drawings to birds and insects found by the artist.

The capture process

Scanners differ significantly from digital camera
Digital camera
A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...

 in many areas. First, the optical resolution
Optical resolution
Optical resolution describes the ability of an imaging system to resolve detail in the object that is being imaged.An imaging system may have many individual components including a lens and recording and display components...

 of a flatbed scanner can exceed 5000 pixels per inch (200 pixels per mm). Even at a relatively low resolution of 1200 pixels per inch (47 p/mm) a letter
Letter (paper size)
Letter or US Letter is the most common paper size for office use in several countries, including the United States, Canada, Mexico, Bolivia, Colombia, Venezuela, the Philippines, and Chile. It measures 8.5 by 11 inches ....

 sized image would be 134 megapixels in size.

The 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...

 of most scanners is very limited, usually no more than half an inch (12 mm), but the built-in light source provides excellent sharpness, color saturation, and unique shadow effects. The time it takes the scanning head to traverse the bed means that scanners can only be used to capture still objects, and common items used are flowers, leaves, and other suitable "still life" subjects.

Equipment

Using a flatbed scanner to scan items other than paper documents exceeds the original purpose of the scanner, so special care must be taken with the process. The bed of the scanner is typically made of glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...

, and care needs to be taken that the glass not be scratched or cracked when placing or removing items on the bed. Since the items to be captured are often placed directly on the bed, dust and other particles will often land on the glass, and care must be taken to keep the glass clean. Scanners will also hold only a limited amount of weight, and items that may damage the scanner, such a liquids or items that might scratch the glass, should be placed on a plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

 barrier to protect the bed. Alternatively, picture frame glass cut a few nches larger than the scanner housing will protect the platen and the device from weeping botanical specimens, paints, melting ice, burning leaves or whatever the challenge.

There are only two standard flatbed scanner sizes: "document" (slightly larger than a sheet of letterhead size paper and "large format" approximately the size of two sheets of paper side-by-side. Many scanners advertise two resolutions, an optical resolution and a higher resolution that is achieved by interpolation
Interpolation
In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points....

. A higher optical resolution is desirable, since that captures more data, while interpolation can actually result in reduced quality.
The higher the resolution (meaning the number of pixels, "ppi"), the larger the print size.

Flatbed scanners typically have a hinged cover that covers the bed, and reflects light back into the scan head. This cover is usually removed or propped open when scanning 3-D objects, to prevent damage or compression of the subject. Removal of the cover also allows the artist to use additional light sources positioned above the bed, which can be used to enhance the depth captured by the scanner.

Scanners can also be modified to provide additional capture abilities. For example, the scanner, with the illumination removed or disabled, can be used as a giant CCD replacement, producing a large format
Large format
Large format refers to any imaging format of 4×5 inches or larger. Large format is larger than "medium format", the 6×6 cm or 6×9 cm size of Hasselblad, Rollei, Kowa, Pentax etc cameras , and much larger than the 24×36 mm frame of 35 mm format.The main advantage...

 digital camera back
Digital camera back
A digital camera back is a device that attaches to the back of a camera in place of a film holder and contains an electronic image sensor. This lets cameras that were designed to use film take digital photographs...

 at a fraction of the cost of professional large format systems.

Techniques

The simplest use of the scanner, which also most closely matches its use for document capture, is as a specialized tool for macro photography
Macro photography
Macrophotography is close-up photography, usually of very small subjects. Classically a macrophotograph is one in which the size of the subject on the negative is greater than life size. However in modern use it refers to a finished photograph of a subject at greater than life size...

. As long as the subject can be placed on the scanner bed, the scanner is excellent for capturing very high resolution images, within its limitations. This also has a very practical applicaton, as it can be used to make images of items being sold on auction sites such as eBay which are too small to be easily photographed with consumer level digital cameras.

A common artistic use of the scanner is to capture collage
Collage
A collage is a work of formal art, primarily in the visual arts, made from an assemblage of different forms, thus creating a new whole....

s of objects. The objects are arranged by the artist on the scanner bed, and then captured. Since the artist is working from the back of the image, it can be difficult to get the desired arrangement. Scanning software with the ability to generate a low resolution preview scan can help in obtaining the desired arrangement before the final, high resolution scan is made.

Since the subjects are often placed in contact with the scanner, there is a high potential for damage to the scanner from objects scratching or cracking the surface of the bed, or from liquids that might seep from the subject into the interior of the scanner. These risks can be mitigated by placing a layer of transparent protective material, such as clear plastic film, onto the scanner bed. Another approach is to invert the scanner, so the bed is above the subject and not quite in contact with it.

Capturing a moving subject with the scanner can be viewed as a problem, or as an opportunity for artistic effect. As the subject moves during the scan, distortions are caused along the axis of the scan head's movement, as it captures different periods of the subject's movement line by line in a manner similar to slit-scan photography
Slit-scan photography
The slit-scan photography technique is a photographic and cinematographic process where a moveable slide, into which a slit has been cut, is inserted between the camera and the subject to be photographed.-Use in cinematography:...

. The artist can use this by aligning the direction of the scan head's movement to deliberately caused the desired distortion.

Stereoscopic Scanning

A variation of macrophotography involves using the scanner to produce stereoscopic or "3D" images of small objects. This is made possible because of the optical system of a typical scanner, which uses prisms to put the sensor at an optical distance from the glass of 3 to 4 feet, allowing a small sensor to cover the entire width of the bed, while keeping the bed physically shallow. This also gives better than expected depth of field, and introduces a certain amount of parallax when the same object appears at different positions on the bed. This allows the generation of stereo pairs, much like the "shift" technique where a single camera is shifted to produce right and left views of a still life scene.
The earliest documented use of this technique was by Bob Wier on Dec 14, 1995, though he makes vague reference to earlier experiments by others. Though it could be described as a trivial application of a centuries old technique to a new device, the concept is not widely known, even among stereo photography enthusiasts. This may be due to the common misconception that the typical flatbed scanner uses an imager that spans the width of the bed, thus leading to the assumption that shifting objects would not produce parallax.

The most basic version of this technique involves simply placing the object upside down on the scanner and moving it by hand, but this leads to irregularities between the two images. Better results can be obtained by placing the object in a glass front display box and sliding the box against a straight edge. Smaller objects such as seeds can be placed on a microscope slide and secured using small adhesive labels. Another, more involved technique is to remove the lid and turn the scanner upside down, then move the scanner rather than the subject. This allows the imaging of extremely flexible objects as well as objects such as small plants which cannot be turned upside down. A variation of this method was used in a patented system which involved mechanically moving an inverted scanner to generate multiple views to produce 3D lenticular artwork. This was marketed briefly as a "lenticular starter kit." The product has since been discontinued but the inventor continues to use it to produce his own artwork.

Images generated this way can be edited with stereo imaging software and viewed as traditional stereo pairs or can be converted to any of a number of formats, including anaglyphs, which are viewed using common bicolor 3D glasses, such as those often used with 3D TV and printed materials. Anaglyphs can be printed with normal printers and used as 3D posters.

The high resolution of consumer level flatbed scanners allows taking stereoscopic images of objects that would otherwise be possible only through a stereo microscope, with similar limitations involving depth of field. The scanner, of course, does not feature adjustable focus, so the sharpest focus will always be closest to the glass.

A wide variety of objects have been stereographed in this fashion, including figurines, fulgurite
Fulgurite
Fulgurites are natural hollow glass tubes formed in quartzose sand, or silica, or soil by lightning strikes. They are formed when lightning with a temperature of at least instantaneously melts silica on a conductive surface and fuses grains together; the fulgurite tube is the cooled product...

s, fossils, mineral specimens, seeds, and even coins

Further manipulation

While the result of a scanner capture provides a work of digital art
Digital art
Digital art is a general term for a range of artistic works and practices that use digital technology as an essential part of the creative and/or presentation process...

, just as a digital photograph does, further manipulation of the captured image is possible as well. This may be as simple as flattening the background to enhance the "floating" effect provided by the scanner to complete reworking of the image.
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