Moirés

There are countless variations of these interference patterns, whose structures are based on the structures of their interacting arrays, and the spatial and angular relationships that exist between them. The types of patterns I'm interested in are created from linear or rectilinear arrays of elements, or screens, in angular alignment. What I've discovered (more correctly, rediscovered, for it's been known for the better part of a century or more) and studied extensively is the fact that patterns created from two screens in angular alignment but with a slight separation between them, will appear to float in space either in front of or behind the interacting screens, at a position determined by the screens' rulings and the distance between them. The floating moiré space thus created and the patterns that inhabit and define it, like the normal 3D space we inhabit, are delimited by a set of mathematical rules that can be used to predict how certain configurations will appear.
    Another feature of moiré patterns that is essential to my work, is the fact that a screen made of repeated or similar images will create a pattern composed of the same (but much enlarged) images, if it is made to interact with a screen whose elements consist of the smallest openings possible for the particular type of screen: dots or pinhole openings for rectilinear screens and lines or slits for linear screens. I call such a set of matched screens an image screen/reference screen (I/R) pair.
    For a given I/R pair, pattern image definition is inversely related to the size of the reference screen's openings compared to their spacing. Thus, the diameter of a rectilinear screen's dots or the width of a linear screen's lines, determine how sharp the resultant patterns will appear: the smaller the dimensions, the sharper the pattern images. Unfortunately, as a reference screen's openings decrease in size, the amount of light they transmit decreases as well. For rectilinear screens, this decrease is geometric: every time a dot's diameter is reduced by a certain factor, its area is reduced by the square of that factor. As a result, a reasonably well-defined rectilinear pattern is very dim, too dim, in my opinion, to be used as an artwork. For linear screens, the situation is somewhat better: as line widths decrease, the light falloff is linear, not geometric, and a compromise can be reached wherein a suitably well-defined but nonetheless bright pattern image can be created.
    When a linear I/R pair is used to create a floating moiré, its geometric properties will be slightly different from those created by the interaction of a rectilinear pair. The three-dimensionality of a floating moiré is the result of the apparent parallax that occurs as one interacts with it (hence the term: paramoiric display). For rectilinear moirés, this parallax occurs in two dimensions, and the resulting pattern appears truly three-dimensional. For linear moirés, the parallax is only in one direction: perpendicular to the lines. But, since our eyes are displaced horizontally from each other, and our ambulatory movement is horizontal, a very convincing three-dimensional illusion can still be achieved by orienting the lines vertically. The space thus created, while not truly 3D (I think of it as 2 1/2 D), has properties of its own that engage the viewer in a very compelling way, but at the same time impose limits on the types of image that can be employed.

Hand Cutting Stencils for Surface Prints

The method I used to create stencils for surface prints required red photographic masking film, an Xacto knife, a T-square, and lots of patience. I would very meticulously cut arrays of lines and squares, usually with ¼ inch spacing, varying their sizes according to how much ink I wanted to deposit in a particular area of the print. I became very intrigued with the idea that a subtle gradation in tonality, something I thought of as qualitative, could be predicted and produced quantitatively, by varying the dimensions of the shapes I was cutting.

Digital Creation of the Shapes for Surface Prints

The digital method I employ for the creation of shapes used in surface prints has much in common with my hand method. A grid work is still used and the shapes employed are still rectilinear, but all the drawing and calculating are performed by a computer. The drawing is done in AutoCAD, a high end drafting program, under the direction of a program I wrote in AutoLISP, AutoCAD's built-in programming language. Through the original template shapes I create, and the variables I enter into the routine, I'm able to control the types of array that are created: the angle, size, and shape of the figures as well as the overall order or randomness exhibited. I can then take the shapes into Adobe Illustrator for colorization and digital output, or, if I'm interested in screen printing, I can cut stencils in photographic masking film directly from AutoCAD, using a customized (and ancient) pen plotter.

Light Rays

Light has a dual nature: particle and wave. I have chosen to ignore its wave properties, refraction and diffraction, and treat it simply as rays: particles that travel in straight lines. In doing so, I'm carrying on a tradition that started with the first camera obscura, made possible the optical drawing devices of the Renaissance that led to the invention of perspective, and is carried on today in the development of 3D rendering software.

Pinhole Camera Design

Virtually any light-tight enclosure can be used as a pinhole camera. While you probably wouldn't want to use one as a means to expose photographic material, a literal Camera Obscura or darkened room is a good way to experience first hand how images can be formed merely by the propagation of light rays through a small aperture. An opening about the size of a dime will allow the creation of a remarkably detailed, if dim, image of the outside world.
    For capturing images on film or paper, any light-tight container will work. Cookie tins and oatmeal boxes are two good examples. It's usually a good idea to make the inside surfaces as nonreflective as possible, either with flat black paint or flocked paper. You can also create your own camera designs from scratch. My favorite construction material for this is black foam core. The key to using it in camera construction is the use of a special rabbit joint cutting tool, with which you can easily cut light tight joints.
    The pinhole itself can be easily constructed by (surprise) poking a hole with a pin. I pride myself on the roundness and smoothness of the holes I create. My technique is to use material cut from a disposable pizza tin, place it on a wood block and puncture it with a needle. I then smooth off the bur on the opposite side using a very fine honing stone. The result is an almost perfectly round hole with smooth edges. This technique was found on the pages of Pinhole Journal, THE source for information and inspiration on pinhole photography. Visit their web site to learn all you need to know on the subject.

Panorama Camera

This is my most elaborate single-imaging camera to date. It consists of an upright cylinder, attached to a base, around which the film is mounted, and a rotating body that supports a pinhole and vertical slit. The body is attached to a Lazy Susan bearing that anchors it to the base while still allowing free rotation. A DC motor, energized by two solar panels, drives the rotation.
    About twenty minutes on a bright sunny day are required to capture an image. The panels can be placed at an angle, sloping down towards the camera's aperture, to provide a certain amount of exposure control: the brighter the scene in a certain direction, the more light will hit the panels, the faster the motor will turn, and the less light will be admitted through the pinhole and slit.
    The camera can capture a fairly detailed image (view 275k image) of a 360-degree scene. One problem this poses: if you're shooting everything in a complete circle, where do you hide if you don't want to be in the picture? I had thought that with such a long exposure, I needn't worry about being caught on film. I was surprised to find that ghostly and distorted images of me kept cropping up. I guess the lesson is: either crouch beneath the camera or dress like a Ninja and keep moving in a direction opposite the camera's rotation.

Digital Output of Pinhole Photographs

Among the things about pinhole photography that appeal to people are its simplicity, its purity. To many, outputting these images digitally seems almost sacrilegious, imposing a number of arbitrary processes between the magical moment of image capture and its presentation. While I agree that there is something special about seeing an image of the world as it was frozen on a piece of photographic material; digital scanning, touch up, and even image editing and color adjustment are just new tools in the photographic process. We're replacing dodging and burning and chemicals with a little digital magic. As far as the output itself, it's approaching and surpassing what's available photographically, both in terms of image quality and permanence, and, for me, it seems appropriate to output images formed by particles of light entering a small aperture, by means of droplets of ink exiting an even smaller aperture.

Multiple Pinhole Camera

My first pinhole camera was, believe it or not, a multiple pinhole camera. In my early days working in prepress 25 years ago, I used screen tints on a daily basis. These sheets of film containing rows and rows of dots were the origin of my interest in moirés as well as pinhole photography. A 5% negative screen tint has dots or openings of a size to admit 5% of the available light: they are very small on even a very coarse screen. I reasoned that such a screen could be the basis of a multiple pinhole camera.
    To create it, I blocked off most of the rows and columns of dots on a 5%, 65 line screen, ending up with an array containing about 5 pinholes per inch. I used a film box for a camera body, loaded it with film, and placed it in front of a copy board on which was mounted my target, a large star shape. After the first test exposure, I thought the experiment had failed. On closer inspection, I found that it was merely overexposed. Luckily, one of the pinholes was partially masked off, forming an aperture of exactly the correct size. My multiple pinhole camera had produced one good image of the star in the copy board, along with reflections of the exposing lamps--my first pinhole photo.
    I later created a (much) more elaborate camera with interchangeable imaging arrays, of dots as well as lines, on glass photo plates, and used this camera to create and study floating image moirés.

Photographic Production of Floating Moirés

The camera I used for the production of floating image moiré screens employed an imaging array of vertical lines, spread 1/8 inch apart, on a glass photo plate. I called this my imaging plate. This plate could be positioned very precisely in front of the film plane, typically from 1/8 inch to 1 inch behind it. The original images I captured were shapes cut in red photographic masking film and mounted on clear glass 20 to 40 inches in front of the imaging plate. They were backlit by a horizontal strip of light about 40 inches wide that was mounted some distance away.
    The images produced by this setup were very elongated versions of the originals. Depending on the exact camera configuration, calculated in advance, these image screens could create moiré patterns that resembled repetitions of the original art and floated in space at a predetermined position. Using this method, I created several screen prints on glass before deciding that the technical problems, as well as the cost, were too great.
    I performed other experiments using slightly different configurations of the same camera. I captured images of various transparent 3D objects, which could be used to reconstruct floating, phantom versions of the originals. I also used imaging plates consisting of rectilinear and random arrays of dots, as well as different light sources, to fully explore the idea of a multiple pinhole camera. The images range from the very simple to my most complex, a multiMEdia array (sorry!).

Digital Creation of Floating Moirés

The digital creation of floating moiré images has much in common with the digital creation of images for surface prints. They're both done in the drafting program, AutoCAD, under the control of a program written in its internal programming language, AutoLISP. To create the images for a floating moiré, I first create a set of shapes in AutoCAD's 3D space. These are the shapes that will be repeated in the floating moiré. I start the routine, enter a number of variables about such things as element spacing, where I want the pattern to appear in space, and total image size, and the program creates two sets of shapes. The first set is made up of the images that will actually comprise the image screen on the final piece. The other set is a preview that simulates how the pattern will appear from a certain point in space. Both sets are brought into Adobe Illustrator. The preview set is used to experiment with the selection and placement of color. Once the colors are decided upon, they are applied to the image screen shapes, and these are output.
    To me, this process is one embodiment of what digital art is about: finding means, in this case by creating a program and also by using existing software, to a desired end. While some aspects of the process are under my total control--I've predetermined where I want certain image elements to be--there is still room for interaction with the software, making it a medium with its own inherent properties.

My Career

Exploring Floating Moirés Further

Every time I see a moiré pattern in the everyday world, usually caused by a picket or chain link fence interacting with itself or its shadow, I have the desire to create large (really large) floating image moirés. They could be effectively worked into a number of different environments, especially those related to people in motion: airports, train stations, playgrounds. They could be effective along thoroughfares as well, although they would probably be distracting and therefore dangerous.
    On a slightly smaller scale, the patterns could be incorporated into architectural design. Since the floating images exist on certain planes in space, they could be made to interact with and enhance architectural elements in very effective ways.
    Creation of pieces like those just described would doubtless require the application of new materials and techniques, but the principals are the same as those I employ now, and the results, at least in terms of imagery, are completely predictable.