Digital Imaging
My work combines traditional and digital photography. There are many misconceptions about digital imaging. Some people think that, because it is "digital," digital photography is necessarily less truthful than, and therefore inferior to, traditional photography. Conversely, others think that digital photography is more technologically advanced than, and superior to, traditional photography. Both of those categorical statements are incorrect.
To better understand how traditional and digital photography interrelate, one should examine three topics: image capture, image correction and manipulation, and image output or printing.
Both digital and traditional photography require a lens to focus light on a plane where the light is then recorded and "captured." Traditional cameras are designed so that light is focused on the film plane. Digital cameras are identical except that light is focused on a plane containing devices that measure light and record its characteristics as a series of numbers, hence the name "digital."
The differences between digital and traditional photography at the stage of image capture are largely practical ones. Both film and digital capture devices (the type of digital capture devices most common today are called "CCDs") have limitations. The biggest drawbacks of film are on-going material and processing costs, grain, and limited tonal range. The biggest drawbacks of CCDs are initial capital costs, digital noise, weight and bulk of the camera and other associated equipment, and, in order to obtain large file sizes, extremely long exposure times.
From my research, I have concluded that, to record enough data in field situations for making high quality, large prints, it is impractical to use digital capture devices in today's (April 2001) market. (In contrast, in many professional studios, digital camera backs have already replaced film.) It would require an investment of upwards of $50,000.00 in equipment that weighs 50-60 lbs. or more to be able to capture as much information as you can capture with a 6cm x 9cm view camera (I use a Horseman VH) that, depending on the lenses and accessories you purchase, only costs about $5,000 and only weighs about 15 lbs. including several lenses, backs, and accessories.
The image above was taken in a canyon called "The Subway" near Zion National Park. The canyon can only be reached by a fairly strenuous 7 mile round trip hike that follows a river fork into the canyon. There is no trail. One must traverse rocks and boulders and cross back and forth from one river bank to the other dozens of times. It would have been very difficult to complete the hike with 50-60 lbs. of camera gear.
Another limitation of using digital cameras to replace medium format or large format cameras (which produce images on film that can contain more than 200 MB of information) is that they require long exposure times; often a minute or more in normal lighting conditions. Moreover, many digital cameras require three separate exposures for each of the red, green and blue channels. Therefore, subjects affected by wind or other movement will virtually always be blurred in high resolution digital prints. (This only applies to professional digital backs that create large image files, holding a quantity of data rivaling the amount of information recorded by professional medium format or large format equipment. For web use or final prints up to as large as 8" x 10", the newest 3 and 4 megapixel digital cameras may already be rendering 35 mm film cameras obsolete for many users. Because the 3 and 4 megapixel cameras record less information than the high end digital backs [recording upwards of 16 megapixels], they also do not require exposures that are significantly longer than 35 mm cameras.)
All this is not to say one can't use high resolution digital cameras in the field. Stephen Johnson has toted a lot of heavy, expensive equipment to National Parks around the country over the last several years and has obtained exquisite photographs in the process. However, for most of us it's just not practical to do so, yet.
For now, if, like me, you want to shoot with a high quality traditional camera and still be able to edit images on your computer and before printing them, you can scan your film. Low quality consumer scanners cost as little as $100.00. Relatively high quality, professional film scanners for 35 mm can be purchased for under $1,500.00. To obtain truly excellent scans that capture virtually all of the information on the original piece of film, you need a drum scanner. The best ones cost upwards of $50,000.00. (Imacon scanners are significantly less expensive and are also very well reputed; they cost in the range of about $15,000.) My scans are currently done on a Linotype Tango Drum Scanner by a service bureau, West Coast Imaging. I send them my 6 cm x 9 cm slides with instructions on how I want them scanned. About 4 business days later, at a cost of about $50.00 a scan, I receive a CD containing files of approximately 160 MB for each image.
To summarize, the first stage of photography is image capture. The differences between digital and traditional photography at this stage are differences of degree, not kind; digital and traditional cameras each offer different competitive advantages. You can also take photographs with a traditional camera and have the images scanned into a digital format.
Image Correction and Manipulation
This is where digital imaging gets a bad name and, in my opinion, undeservedly so. When people say digital imaging, they think of someone using an image editing program to take elements from different photographs, magically "pasting" them together, and trying to pass them off as a traditional, unaltered photograph. Although this may sometimes happen, digital editing is much more often used to facilitate the types of image corrections that have always been performed in the traditional, wet chemical, darkroom.
In one of my favorite photography books, Examples, The Making of 40 Photographs, Ansel Adams discusses forty of his best known photographs and describes the techniques he used to achieve these images within the limitations of traditional photography. His techniques were no less manipulative (a word with negative connotations) than my use of Photoshop for digital editing. For instance, in making "The Black Sun," Adams took advantage of a solarization effect to achieve a dark gray, or black, sun against a much lighter sky. In developing negatives, Adams is famous for having used different types of chemical combinations and different development times on virtually every shot to contract or expand the tonal range of the film. Then, in making prints, Adams dodged and burned, to make some areas darker or lighter than they would have been if he had not corrected or "manipulated" the printing process. There is little doubt that if Adams were alive today, he would own a computer and experiment with digital editing of his photos to alter tonal (and, if he worked in color, color) relationships. After describing the making of "Sand Dunes, Sunrise," Adams stated, "I am sure the next step will be the electronic image, and I hope I shall live to see it. I trust that the creative eye will continue to function, whatever technological innovations may develop."
In the digital "darkroom" it is easier than in a traditional darkroom to change tonal relationships and color. However, much skill is require to maintain the integrity of the image so that it looks real and, in fact, more accurately represents what the photographer saw than the "undeveloped" positive or negative. Because the learning time in a digital darkroom is shorter and the ability to alter the relationships of tone and color in the original is no doubt greater, there is a risk that photographers will overly manipulate images without acknowledging that they have done so. One of the advantages of a craft that requires years to develop is that, along the way to becoming a master, the student inevitably learns to respect and protect the craft and thereby also protects his or her own investment of time and effort in it.
Although I correct tonal relationships and color in my images, I take care (i) not to alter the subject matter (for instance, I do not "paste" clouds from one image into another), and (ii) to keep the overall color balance and tonal relationships true to how I visually remember the scene. The fact that I cannot see much highlight detail in the original transparency of a scene does not mean that I could not see it when I took the photograph; more often it means that the film cannot hold as much detail as the human eye. I see no ethical dilemma in using a computer to correct images in this way.
I am currently experimenting with several, exciting digital techniques. First, when the contrast range of a scene is too great to hold in one transparency, I shoot two exposures of the same shot within seconds of each other. One is properly exposed for the highlights; the other is properly exposed for the shadows. After scanning the two images into the computer, I use Photoshop to paste the two halves together. Again, I see no ethical dilemma in using this process. It is virtually identical to using a graduated neutral density filter; however, it offers greater control and, because there is not an extra piece of glass in front of the lens, does not degrade the image.
A second technique I am beginning to work with is shooting black and white images on color transparency film. Although I learned photography in a black and white darkroom and shot only black and white film for many years, my photography really took off when I started shooting color. Because of my emphasis on color, however, I don't carry black and white film anymore. Sometimes, however, after looking at an image on the light table, I wish I had shot it in black and white. In fact, I have! When you scan a color image (I shoot primarily Velvia slide film) into the computer, it is translated into three different tonal scales, one each for the red, green and blue channels. The r, g, b channels approximate what you would obtain if you shot the image with black and white film and, respectively a red, green, or blue filter. The first step in creating the above image (which you can compare to the color version, click here) was to copy and paste the red and green channels into new layers of a Photoshop document and then, after experimenting with different tonal effects, settling on a gray scale image created using 85% of the red layer and 15% of the green one. This precise tonal relationship would be virtually impossible to achieve using traditional black and white materials.
After adjusting the gray scale image to achieve appropriate tonal relationships, I added a slightly blue duotone. (I've exaggerated the duotone a bit too much for the Internet to ensure that viewers with uncalibrated monitors can see the effect.) In the traditional darkroom, it's necessary to experiment extensively with different papers and toning effects for many months or years before being able to achieve even a modicum of control in toning photographs. It's very easy to master duotone effects in Photoshop.
Digitally editing a photograph offers greater control than a traditional darkroom. When used appropriately, digital imaging does not, in my opinion, create ethical problems. By the same token, both digital imaging and traditional darkroom techniques can be used for improper purposes.
In a traditional darkroom, the photographer puts the negative (or less often the positive) in an enlarger, and, using an enlarger light, projects light through the negative and enlarger lens onto light sensitive paper. The paper is then developed in various chemical processes to make a print.
With digital imaging, there are two ways to make a print. First, you can simply print the digital file on a desktop (most often, inkjet) printer. In contrast to traditional color printing that contains dyes in the paper which are then developed in chemicals, an inkjet printer applies dyes (or more recently pigments) onto the paper.
The second way to make a print with digital imaging uses a process almost identical to the traditional darkroom. There are high end printers, the best of which are the Lightjet 5000 and Durst Lambda, that use lasers to expose traditional photographic paper; the exposed paper is then developed in the same chemical process used in traditional darkrooms.
Until early 2001, I had eschewed using inkjet printers because of longevity concerns. Inkjet prints have notoriously faded very quickly. By contrast, prints made on Fuji Crystal paper using a Lightjet 5000 are rated to last approximately 60 years before any noticeable fading occurs (traditional Cibachrome prints are rated to last about 30 years). Epson and various third parties have recently introduced pigmented ink sets that offer tremendous resistance to fading; depending on the paper used, the Epson inkset is rated to last as long as 200 years. I recently retrofitted an Epson 1200 with a continuous inking system and third party color pigmented dyes marketed by Mediastreet. The quality is phenomenal and rivals prints I can obtain on a Lightjet. It also offers several significant advantages over using an outside service bureau to make digital prints. First and foremost, having a printer on my desktop encourages me to experiment and take more chances. Second, I am able to control the process from beginning to end, and therefore can obtain a print that more closely approximates what I envision. Third, inkjet printers allow you to use different papers, including specially coated watercolor papers, for different textures. The possibilities seem limitless.
Digital printing offers tremendous advantages over the traditional darkroom when it comes to color printing. It is extremely difficult to burn and dodge in a color (as opposed to black and white) darkroom because when you alter tonal relationships, you usually also end up getting undesirable color shifts. The computer allows the photographer much more accurately to control this process.
Color Calibration for the Digital Darkroom
To realize the tremendous technical advantages possible with digital imaging, it is necessary to calibrate the color and tonal renderings of your monitor and printing devices you are using. In my experience it is extremely difficult and time consuming manually to correct the color of an image when you cannot rely on your monitor to portray accurate color and your printer to closely approximate what you see on your monitor. Developing a calibrated workflow requires an investment of time and money, but, if you intend to do serious digital imaging work, the investment should be worthwhile. The technology that makes it possible to create a calibrated workflow on the Macintosh is called colorsync; Apple's website for colorsync is a good place to begin learning about color calibration issues. The best book for understanding color calibration on the computer as well as other advanced Photoshop issues is Real World Photoshop by Blatner and Fraser. If you get serious about creating a digital darkroom, you will eventually want to purchase third party products that utilize the architecture created by Apple's colorsync technology. I use Optical and an Xrite Monitor Optimizer (a hardware puck that measures the light emitted from my monitor) to calibrate my monitor. Many scanners, like my Microtek Scanmaker 5 scanner, come with easy to use utilities for calibrating your scanner. My service bureau provides me with profiles that accurately describe the output from their printer, a LightJet 5000. For my inkjet printer, I have purchased a couple of custom made profiles. Although "canned" profiles are often available for free, to get really accurate color you will want to have an expert make custom profiles for your particular printer and each paper/ink combination that you use. It's well worth the time savings.
In practice, I can scan a slide and have it appear on my monitor in about two minutes with 90%+ of the color and tone of the original slide. I then make corrections, clean dust and scratches, and make other changes in Photoshop to more accurately approximate my memory and excitement with the scene. I use a keyboard command in Photoshop to quickly see a "softproof" rendition of the image. The softproof limits the color and tonal range of my monitor to simulate the result from outputting the image on an inkjet, Lightjet 5000, or other profiled printer. Thus, within about 15 minutes, I am able to create a file that I can then print on my inkjet or send to my service bureau (NancyScans) for an initial 11" x 14" print of an image. This quickly made "proof" is almost always better than the best prints I was previously able to obtain by sending my work to a highly regarded custom printer for traditional photographic prints.
After examining this initial "proof," if I want to create a fine art print, I send the slide out to be drum scanned. When I receive the drum scan I typically spend many hours, or days, fine tuning local tone, contrast, and color before I send out an initial file for a test print. I usually go through at least five rounds of test prints from these drum scanned files before I am satisfied and make final prints of an image.