Materials And Processes Technical Considerations And Visual Outcomes
As stated in the introduction, this book is about the four elements that comprise the technical foundation, as well as dictate the visual outcomes, of all photographic images. They form what I refer to as the grammar of photographic language. Framing, focus, and the rendering of time and motion are all associated with image capture, but are also controlled in post-capture image production. The final element, materials and processes, is different from the first three in that this element is not controlled through the camera mechanism, but it is integral in that materials and processes is the very stuff of which the image is made. Included in this discussion are aspects of the physical object that are important in forming the image. There are three primary aspects of this photographic element: grain structure; surface structure (tint, tone, and texture); and size and scale. Additional discussion is devoted to the impact of the viewing space on the image.
Grain Structure
Since light-sensitive media is itself a physical object, its surface texture and physical composition impact the quality of the image it captures, literally imposing an image of its own physical nature into the image it captures. Both traditional film and digital sensors have similar characteristics pertaining to light-gathering ability and its effect on images; "grain" is not the technically correct term for referring to the makeup of digital sensors, but for this discussion it helps to think of a digital sensor as being composed of millions of evenly spaced, identically sized light-gathering particles.
The light-gathering ability of photo-sensitive media is rated by the International Standards Organization (ISO); the lower the ISO rating for a given media type, the slower the media responds to light to record an image. ISO numbers are explained at length in Appendix B of this text. As a general rule, slower ISOs produce images with finer grain (traditional) or noise (digital); faster ISOs produce images with larger or more apparent grain or noise. The reason for this is that with traditional film, the faster the ISO, the larger the actual grains of silver have to be; this provides a larger surface area for light to render adequate exposure faster. With digital media, the effect is similar—increased noise with increased ISO—but the reason is different; digital sensors are optimized at their slowest ISO, and the electrical signal created upon exposure to light is amplified when you move to higher ISOs, thus rendering faster exposure but with noisier image quality.
There are two other image quality considerations related to light-sensitive materials. They are resolution and acutance.
Resolution refers to the material's ability to produce a detailed image; acutance refers to the material's ability to produce fine edges and transitions between tonal differences. In general, the slower the ISO the finer the resolution and acutance, but other factors such as lens quality and differences between media—say, slide film versus negative film, and digital sensor types—are also significant.
The following example represents an image captured digitally at both 100 ISO and 1600 ISO sensor speed ratings. The blow-up versions show the increased noise caused when a faster ISO is used.
- PHOTOGRAPH ©ANGELA FARIS BELT, 2007.
Generally speaking, photographers choose the ISO rating that best suits the lighting condition and exposure needed, but often the decision about ISO can be made for purely aesthetic reasons. For example, consider that since slower ISO media creates a finer image, it might communicate more seamlessly or transparently about a subject, while faster ISO media might draw a viewer's attention to itself through added texture. In addition to the capture material's ISO characteristics, the processes used in the traditional or digital darkroom can emphasize either extreme. Using the materials and processes together enhances your ability to communicate to your viewer.
Imagery about difficult subjects, for instance poverty, war, disease, social injustice, or violence, created with the grainy, gritty texture of the materials enhanced, transmits a more concrete and visceral experience to a viewer than could the same imagery using the finest grain structure. The potential impact of maximizing the light-sensitive material's structure is apparent in Robert Frank's Hoe Americans, and is underscored in the storm of American public response to the work. More recently, it is powerfully utilized in Jim Goldberg's Raised by Wolves, a social documentary account of San Francisco and Los Angeles inner cities' homeless teens. The images use grain as a communicative element, since
- 100 ISO renders finer image quality. ENLARGED VIEWS.
smooth, silky imagery that minimizes the light-sensitive material's structure is in many ways at odds with the intellectual and emotional response their subject should evoke.
Surface Structure (Tint, Tone, and Texture) A second significant aspect of the materials and processes from which the photographic image is made has to do with the surface structure of the image—the hue (actual color),
- 1600 ISO renders rougher image quality.
value (relative degree of light or dark of the color), and intensity (the saturation or purity of the color) of both the substrate and the image material, as well as their texture. These are considerations even when the image is said to be black and white, because neither the substrate nor the image material may be a pure neutral tone, and even a subtle degree of color can make a dramatic impact on the feeling of an image.
That the surface structure so dramatically affects the appearance of the final image is a reason enough to understand its nature, since the appearance of the image affects its interpretation. Understanding how color forms in a photograph does not take a degree in chemistry, but only the ability to research the materials you wish to use. Although the two terms are often used interchangeably, for this discussion, I will use the term tint to refer to the substrate's color characteristics (the paper, fabric, etc., that the image is printed on), and I will use the term tone to refer to the color characteristics of the image material (the inks or emulsions that form the image).
Tint: This refers to the paper or substrate's density and color characteristics including its hue, value, and intensity. Some papers look warm, some neutral, and others cold. Some papers look bright white, some natural white, and others dingy white. Alternative printing materials can also be used, such as linen and other fabrics, 3-dimensional substrates, and even clear glass, to which photo-sensitive emulsions are added. It should be understood as well that the tint of the substrate is often responsible for the perception of contrast in the image.
The tint of the substrate is a factor in both traditional and digital imagery. While pre-sensitized substrates for traditional darkroom use are becoming more limited, coated inkjet substrates are becoming more varied. Rather than use coated substrates for inkjet printing, some artists use traditional watercolor papers and other materials for printing with inkjet technology, and others are transferring inkjet prints from one substrate onto another similar to Polaroid Transfer techniques. The results of these printing methods vary widely, and experimentation is required for greater understanding and control.
Tone: This refers to the color characteristics of the image material; these are the inks, dyes, or emulsions that form the image on the substrate.
When using chemical emulsions, the degree of light sensitivity (how fast or slow the emulsion responds to light) might be a consideration that limits aesthetic choices about tone. Additionally, the chemical processes used in developing the prints affect the color of the image. There are three basic emulsion formulations of black and white darkroom printing papers, though the numbers of available papers are dwindling.
1. Chloride emulsions'. These emulsions are generally used for contact printing, as they have slow sensitivity to light and will often fog before an enlargement can be made. They tend to produce warm tones, and can be used for split-toning using a heavy selenium bath.
2. Bromide emulsions'. These emulsions are generally used for making enlargements, as they are more sensitive to light. They tend to produce a more cold tone print.
3. Chloro-bromide emulsions'. These emulsions are a mixture of the previous two, and can produce exposure and color qualities anywhere in between, depending on the ratio of chloride to bromide.
Texture: Substrates, emulsions, and other image materials have texture that imprints itself onto the final image. Textures range from smooth, slick, high gloss, to toothy matte; they have a dramatic effect on how the image tone is applied to the material as well as on the reflective value of the surface. They also affect how the materials must be handled, since many more glossy materials must be handled with extreme care as they are prone to surface scratches. High gloss materials often are associated with commercial photography applications while more matte surfaces carry with them connotations of hand-made quality.
Various tints and tones, as well as surface textures of prints greatly affect image appearance, thereby influencing how the viewer interprets the image. Decisions regarding these
PHOTOGRAPH © ANGELA FARIS BELT, LUNA MOTH, 2006.
Clockwise from upper left: Hie original color image, a grayscale version, a split toned version, and sepia toned version.
aspects of image production are important throughout the process, and research and experimentation are invaluable guides.
Digital Darkroom Grain and Sepia Effect
Although digital sensors are capable of producing very fine detail, sometimes that's not what you need to make your images work well. Sometimes you want grain or noise to add perceived texture to the image, and there are ways to enhance it in the digital darkroom. The "Grainy Effect" tutorial found in the Tutorials Section for Chapter 4 walks you through a simple procedure developed by one of my students, Jennifer Hardman.
Size and Scale
Materials and processes determine important aspects of the appearance of photographs precisely because we relate to them physically in a visual sense. The image's appearance affects us, not only because of its subject and content, but also because of its form, including all of the physical attributes of the image. One of these attributes, which exists somewhat outside of materials and processes, is the size and scale of the image. Just as the aesthetics of focus range from uber-sharp to unrecognizably diffused, the aesthetics of size and scale also display a range. But the determining factor for the size of images shouldn't depend on the current trend; rather, it should depend on factors such as practicality (what is the end use of the image and what is an appropriate size for this end use) as well as how the size of the image content relates to its viewers, and what the size of the image says about the subject.
Susan Stewart, in her critical text On Longing: Narratives on the Miniature, the Gigantic, the Souvenir, the Collection, states that, "The body is our mode of perceiving scale." Our perception of the size and scale of anything outside our bodies is relative to our own (human) size. Stewart says that, "The miniature is considered ... as a metaphor for the interior space," it is personal, secretive, sensual, private as a family snapshot and nearly as sentimental. "The gigantic," on the other hand, "is considered as a metaphor for the abstract authority of the collective state and the collective, public life"; it is engulfing, overpowering, open to all and thereby impersonal.
Two contemporary artist-photographers come to mind when discussing size and scale relative to the content of images. Andreas Gursky, the German photographer, is known for photographing public spaces, retail stores, and large landscapes from high vantage points. He has printed images at an enormous scale, sometimes exceeding 6 ft at
Before and after the Grain effect is applied. PHOTOGRAPHS © JENNIFER HARDMAN, HANDS, 2007.
their minimum dimension, by combining several oversized sheets of photographic paper. The photographs, like the places depicted in them feel public. Their saturated color and crisp detail throughout packed frames is almost overwhelming, and commands perhaps more tactile presence than would the scene itself. At the opposite extreme is Japanese artist Masao Yamamoto's ongoing series of photographs entitled A Box of Ku. There are hundreds of unique images in the series, each small enough to fit in the palm of a hand. In this work, not only is the scale that of a personal souvenir, but the print surfaces are manipulated to feel as though each has had its own life in the world; they are torn, creased, stained, and feel as though they have lived in a pocket. The scale makes the work feel simultaneously universal and personal, and speaks to the understated beauty of the individual print's varied and enigmatic content.
Continue reading here: Artist Statement Xne
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