Non-digital photographs are produced with a two-step chemical process. In the two-step process the light-sensitive film captures a negative image (colors and lights/darks are inverted). To produce a positive image, the negative is most commonly transferred ('printed') onto photographic paper. Printing the negative onto transparent film stock is used to manufacture motion picture films.
Alternatively, the film is processed to invert the negative image, yielding positive transparencies. Such positive images are usually mounted in frames, called slides. Before recent advances in digital photography, transparencies were widely used by professionals because of their sharpness and accuracy of color rendition. Most photographs published in magazines were taken on color transparency film.
Originally all photographs were monochromatic, or hand-painted in color. Although methods for developing color photos were available as early as 1861, they did not become widely available until the 1940s or 50s, and even so, until the 1960s most photographs were taken in black and white. Since then, Color photography has dominated popular photography, although black and white is still used, being easier to develop than color.
Panoramic format images can be taken with cameras like the Hasselblad Xpan on standard film. Since the 1990s, panoramic photos have been available on the Advanced Photo System film. APS was developed by several of the major film manufacturers to provide a film with different formats and computerized options available, though APS panoramas were created using a mask in panorama-capable cameras, far less desirable than a true panoramic camera which achieves its effect through wider film format. APS has become less popular and is being discontinued.
The advent of the microcomputer and digital photography has led to the rise of digital prints. These prints are created from stored graphic formats such as JPEG, TIFF, and RAW. The types of printers used include inkjet printers, dye-sublimation printer, laser printers, and thermal printers. Inkjet prints are sometimes given the coined name "Giclée".
Preservation
Paper folders
Ideal photograph storage involves placing each photo in an individual folder constructed from buffered, or acid-free paper. Buffered paper folders are especially recommended in cases when a photograph was previously mounted onto poor quality material or using an adhesive that will lead to even more acid creation. Store photographs measuring 8x10 inches or smaller vertically along the longer edge of the photo in the buffered paper folder, within a larger archival box, and label each folder with relevant information in order to identify it. The rigid nature of the folder protects the photo from slumping or creasing, as long as the box is not packed too tightly or under filled. Folder larger photos or brittle photos stacked flat within archival boxes with other materials of comparable size.
Polyester enclosures
The most stable of plastics used in photo preservation, polyester, does not generate any harmful chemical elements, but nor does it have any capability to absorb acids generated by the photograph itself. Polyester sleeves and encapsulation have been praised for their ability to protect the photograph from humidity and environmental pollution, slowing the reaction between the item and the atmosphere. This is true, however the polyester just as frequently traps these elements next to the material it is intended to protect. This is especially risky in a storage environment that experiences drastic fluctuations in humidity or temperature, leading to ferrotyping, or sticking of the photograph to the plastic. Photographs sleeved or encapsulated in polyester cannot be stored vertically in boxes because they will slide down next to each other within the box, bending and folding, nor can the archivist write directly onto the polyester to identify the photograph. Therefore, it is necessary to either stack polyester protected photographs horizontally within a box, or bind them in a three ring binder. Stacking the photos horizontally within a flat box will greatly reduce ease of access, and binders leave three sides of the photo exposed to the effects of light and do not support the photograph evenly on both sides, leading to slumping and bending within the binder. The plastic used for enclosures has been manufactured to be as frictionless as possible in order to prevent abrading and scratching the photos during insertion to the sleeves. Unfortunately, the slippery nature of the enclosure generates a build-up of static electricity, which attracts dust and lint particles. The static can attract the dust to the inside of the sleeve, as well, where it can scratch the photograph. Likewise, these components that aid in insertion of the photo, referred to as slip agents, can break down and transfer from the plastic to the photograph, where they deposit as an oily film, attracting further lint and dust. At this time, there is no test to evaluate the long-term effects of these components on photographs. In addition, the plastic sleeves can develop kinks or creases in the surface, which will scratch away at the emulsion during handling.
Handling and care
It is best to leave photographs lying flat on the table when viewing them. Do not pick it up from a corner, or even from two sides and hold it at eye level. Every time the photograph bends, even a little, this can break down the emulsion. The very nature of enclosing a photograph in plastic encourages users to pick it up; users tend to handle plastic enclosed photographs less gently than non-enclosed photographs, simply because they feel the plastic enclosure makes the photo impervious to all mishandling. As long as a photo is in its folder, there is no need to touch it; simply remove the folder from the box, lay it flat on the table, and open the folder. If for some reason the researcher or archivist does need to handle the actual photo, perhaps to examine the verso for writing, he or she can use gloves if there appears to be a risk from oils or dirt on the hands.
Cultural misconceptions
Susan Sontag suggested that while painting can only ever be a "narrowly selective interpretation", a photograph can be treated as a "narrowly selective transparency". A painting is dependent on a number of subjective variables such as personal ability, subject selection and personal interpretative techniques. Although photography encompasses fewer of these variables, it is not exempt from subjectivity.
The sheer quantity of concepts and principles and photography techniques demonstrates how a photograph can provide alternate meanings. Sontag suggested that even when photographers are concerned only with mirroring reality, they are still preoccupied with taste and conscience. As seen in the Farm Security Administration of the 1930s, deciding which exposure should be selected, which should not, is imposing a set of standards on the subject.
Peter Doyle elaborates that photography now attracts a learned suspicion. The adage "a photo never lies" is increasingly tested as digital photography becomes the photographic standard, including its inherent ease of manipulation.
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