Photoethnography blog

In rooting around this morning, I found the following blog, by Karen Nakamura, a cultural anthropologist who uses documentary photography as a key component of her fieldwork. Her site has some very useful discussions of equipment and technique that, though geared primarily to making photographs of people, are also relevant to those of us who shoot buildings.

Her photographs, additionally, are very affecting. Those of us whose work centers on the relationship between buildings and people can learn from the way she presents human activity in particular environments. Look here (select “Top Twelve”) for the photograph of a carpenter at work and an old couple outside their house in Shanghai, for starters.

Faking Pictures in Photoshop

Skeptics about the merits of digital photgraphy for architectural documentation have noted the ease with which images can be manipulated in Photoshop. The classic complaint is that if it’s so easy to remove things like power lines, how can we trust that any digital image is an accurate representation of a building? Well, I suppose we can’t, if somebody is especially determined to pull the wool over our eyes.

This is, according to the Chronicle of Higher Education, a much larger problem in the sciences, where journal editors, working with the Federal Office of Research Integrity have developed software tools to detect digital fakery in submitted evidence.

I’m reminded of the widespread concern in the 19th century over spirit photography, which cast much doubt over the veracity of photography in general, because its images of ghostly figures seemed so real. The New York trial of William Mumler was an attempt to rescue photography from the stain of fakery and to establish its status as a truthful form of representation and a legitimate, scientific tool (see Michael Leja’s Looking Askance for a full and nuanced account of the Mumler trial and its context) .

For the purposes of documentary architectural photography, it is certainly legitimate to ask what the appropriate limits are to digital manipulation. Is it alright to remove dust spots? What about adjusting color balance? What about cropping and stretching to remove parallax? All of these are easily done (though sometimes time consuming) within Photoshop, which includes tools specifically for this purpose. The “Magic Healing Brush” allows a user to select a spot–a piece of dust in an otherwise spotless blue sky, or a bird, say–and remove it with one click. The crop tool includes a perspective adjustment, which makes it simple to turn buildings that are afflicted with parallax distortion (ie, they look like trapezoids) into perfect upright rectangles. This is to say nothing about adjusting exposure and contrast, or adding sharpening, or creating panoramas, or assembling high-dynamic-range composites.

So what are the acceptable limits to image manipulation for documentary photography (here i refer to images shot digitally, not scans of slides or prints, which require a different, much tighter standard)? Clearly, insisting on preserving the image just as it came from the camera makes little sense. No one has any problem with a film photographer’s choosing a particular film for its highly saturated colors, or a particular chemical bath, or for using a high or low-contrast paper for processing, etc. So clearly, we should be comfortable with a certain amount of manipulation that allows the photographer to present the image as he or she intended to capture it.

I, for one, routinely tweak exposure settings slightly, as well as contrast, and frequently color balance, at least on interior shots, where multiple light sources (flash, incandescent, daylight) complicate color considerably. Since I always shoot in raw format, which produces a soft image, I add some judicious sharpening as well. Sometimes I find that, despite my best efforts to get vertical lines to be vertical, that I have some parallax distortion, as well, and I need to do some minor perspective adjustments. For a discussion of the merits of and means to perspective correction in Photoshop, see this discussion. Finally, when I had a relatively cheap lens, I found that it was almost always necessary, when photographing buildings, to remove pincushion or barrel distortion, a task that is automated by the marvelous ptlens tool (if you need it, get it. There’s nothing better).

That’s really about it. I don’t fiddle around trying to remove power lines, or cars, or people. Every now and then, I might burn in and blur someone’s face but on the whole, I try to get the shot right in the camera, framing my views carefully and adjusting exposure in the field. Here’s one where I was in too much of a hurry and didn’t get it framed right. Cropping the lines out would have removed too much sky, so needless to say, I was sorely tempted to try to zap them. Sometimes, of course, there’s nothing you can do. And a lot of people, it turns out, are actually interested in photographs of power lines.

I should emphasize that all of the adjustments I make tend to be subtle. It quickly becomes obvious when you fuss with an image a lot, and even when manipulations are well done, they tend to call attention to the technique, as opposed to the building. I don’t do perspective adjustments that require distortions of more than 10%, and I try not to do them at all (as David Ames advises, it’s always preferable, when trying to capture a tall building, to frame your shot vertically, but sometimes that’s not enough). Exposure adjustments above about one stop start to reveal and emphasize noise. And trying get rid of people, cars, etc. convincingly is a fool’s errand, unless you’ve got tons of time on your hands (digital image manipulation in the context of architectural documentation is seriously subject to the law of diminishing returns).

So yes, it’s technically possible to fake a photograph of a building, and photorealistic images are now possible of buildings that don’t even exist, thanks to high-end CAD and rendering software, but wouldn’t you rather spend your time doing research, or in the field? I would.

Edit: For what it’s worth, in the most recent New Yorker, Sasha Frere-Jones discusses Auto-Tune, one of many goodies in the modern music-producer’s tool box, in terms that are analogous to the documentary photographer’s use of Photoshop. The photograph is always a transformation of a thing, in the same way that a recording, even of a live performance, is a transformation. The degree and nature of that transformation varies, but photographs, like recordings, are always mediated.

2008 William and Mary/CWF Fieldschool in Architecture

Prospective scholars of early American architectural history, take note:

For the current 2009 fieldschool announcement, see here.

College of William and Mary and Colonial Williamsburg Foundation

Architectural Field School, History 490/590

June 30-August 1, 2008

Williamsburg, Virginia

Carl Lounsbury, Instructor

The Colonial Williamsburg Architectural Research Department in conjunction with the College of William and Mary’s National Institute of American History and Democracy offers a five-week course this summer that is open to all undergraduate and graduate students. This field school introduces students to the methods used in the investigation and recording of buildings. On-site examination of structures in the Historic Area of Williamsburg and visits to buildings in the surrounding Tidewater region follow several introductory lectures on building technology and architectural features. The program is intended to help students distinguish the form, fabrication, and assembly of materials and building elements and understand their chronology. They will learn how to apply field evidence to answer larger questions concerning architectural and social history.

The fourth week is devoted to investigating and recording buildings on location away from Williamsburg. The field school will return to Beaufort, South Carolina, to assist the local preservation society in recording town houses and plantation sites. Back in Williamsburg for the last week, students will convert their fieldwork into measured drawings using a CAD program and write reports on their sites.

This class will meet four days a week from 10:00 to 4:30. It will require travel (in a van) and some physical exercise–mainly climbing and squeezing. Students must be enrolled for the course through the College of William and Mary. The cost of travel and accommodations in Beaufort will be covered by the program. For more information, please email Carl Lounsbury at clounsbury@cwf.org or call (757) 220-7654.

More information, including two research reports from past years, is available on the NIAHD website, here.

Computers and Fieldwork

After being diverted and delayed for 24 hours due to bad weather in Chicago, I returned late last night from the 2008 annual meeting of the Vernacular Architecture Forum in Fresno, CA, where, among other things, I was elected to the board of directors, to thunderous applause. At least that’s how I remember it.

At recent VAF conferences, there have been anxious discussions about the status of fieldwork and the utility of digital technology. These have not usually been brought together until this year, when it happened in three separate sessions, including both of the ones in which I was a panelist (incidentally, does anyone else feel that it’s time for us to extend the number of time slots for sessions from 3 to 4?).

In her discussion of the Gaspe field school, Tania Martin observed, quite pragmatically, that all the new digital gizmos we have at our disposal are only tools, with particular strengths and weaknesses, and that it’s up to us to understand how and when they are useful, and when the old ways are better. Immediately after Tania’s sensible and seemingly uncontroversial remark, two of the other panelists  were both compelled to point out that they didn’t think too much of new technologies in the context of fieldwork, pointing out that they require electricity, for example, and that the visual qualities of hand drawing are superior to CAD drawing.

I suppose this is true as far as it goes, but why do VAF participants still feel they need to advertise their skepticism (or worse, their ignorance) about digital technologies in general? Film cameras require a complex chemical process to make a photograph but that doesn’t seem to bother anyone. We need to call a moratorium on analog posturing at these meetings, like bragging that we don’t have a cell phone. It’s irritating, unproductive, and takes time away from more sensible, thoughtful conversations about our work that are sincerely open to new possibilities.

This conversation might be easier if we re-focused the discussion away from particular technologies, or tools, and toward research activities. The question need not be: is CAD better or worse than ink-on-mylar? It should be: when does CAD help me do my work?

The two techniques that came up in this context on Saturday were CAD and laser scanning. Laser scanning is a form of “remote sensing,” or measuring a thing without touching it. The technology makes use of a spinning laser and a measuring device that is attached to a computer. A technician sticks the device on a tripod, sets it to run, and walks away. For a few minutes, the laser whips around the room, recording distances at regular intervals and passing the results along to the computer. With enough measurements, the system can create a good representation of the space via a “point cloud,” or a series of measured points that can be translated into a 3-D model in CAD software. With the best devices, the point cloud can be dense enough that it captures quite refined details, like molding profiles and door knobs.

It’s a cool technology, especially for developing models of very complex spaces or ornate details, both of which would be extremely laborious to measure by hand. It’s a fantastic way to record the spatial characteristics of a building or a sculpture, for example, and probably the best way to capture, say, the ornate carving on a capitol. The process is time consuming, however, requiring a skilled technician to translate the points into planes and curves. It is, for the moment, expensive. It also fails to record color, and lacks the resolution to pick up cracks and other subtle changes in wall surface that can be important evidence in old buildings. It is not, in short, a replacement for looking carefully. It is a mathematical representation of a building’s formal characteristics that does not make analytical sense of it. If we define fieldwork as a process of understanding a building through recording it, laser scanning is not a great tool for fieldwork.

Clearly, however, it has enormous potential as part of a larger enterprise that includes close looking and careful annotation. In a complex building with many changes, a knowledgeable fieldworker will be required to make sense of how it developed over time and relate that information to the model. The newer, and simpler, the building, the more complete a representation the laser scan becomes. It is surely not a way to record the Peyton Randolph House in all its complexity but it might well capture most of what we want to know about, say, a modern warehouse, or a Target store.

It would be marvelous to have a scan of a building in hand before doing the analytical fieldwork that we still see as fundamental to our scholarship. If a technician can be given the task of making a scaled model, from which one can generate careful scaled plans, sections, and elevations, a field scholar can concentrate on annotating the building with descriptions, notes, etc. I might also add other kinds of documents to the model, such as photographs, allowing it to become the digital framework upon which I hang my analysis.

Modeling, in general, would only ever be one piece of the documentation puzzle. It is a means of representation, not a means of recording. Laser scanning makes modeling simpler, and perhaps makes fieldwork easier, but is not a substitute for fieldwork any more than board drafting is a substitute for field measuring.

And so we return to drawing. Drafting, whether by hand on a board or in a CAD program, is a technical skill. There is no romance to it, nor has there been since the professionalization of architecture in the nineteenth century defined the production of construction drawings as manual wage labor. CAD programs certainly reflect the technical nature of this process and perhaps we are right to resist market-driven definitions of our work.

On the other hand, CAD does bring the production of clear, clean, competent drawings within reach of even the clumsiest of us. We all love to look at a beautiful, hand-drawn illustration, such as the ones by Cary Carson and Chinh Hoang in “Impermanent Architecture” and Tom Hubka’s in Big House, Little House. But the ability to produce such images is a very rare skill. We can’t all be David Macaulay and we delude ourselves if we think otherwise. For most of the drawings that most of us need to produce, a CAD plan is likely to look better than a hand-drawn one, and can be completed much more quickly.

Some of us, to be sure, will continue to derive enjoyment from drawing with ink on a board but for most of the VAF, and for most of our students, it is foolish to imagine that ink-on-mylar has any future beyond a romantic hobby. Those who can draw beautifully will continue to do so, and my hat is off to them. The rest of us will be better served by learning to use the computer.