Stereo on a Shoestring

You can break loose from the constraints of traditional two-dimensional photography without spending more than the price of a couple of "single-use" cameras and the cost of processing.

Purists may scoff, but face it--looking at a 3-D picture is simply more fun. It's more realistic, it puts the viewer right where the photographer was when the picture was taken, and it makes people sit up and say, "Hey, you gotta see this!"

Almost from the beginning of photography, people have been intrigued by the possibility of recreating the verisimilitude of real-life vision with three-dimensional representation.

Maybe you've been around long-enough to recall the thrill of View Master reels--those ingenious pairs of little transparencies mounted on a circular disk and viewed sequentially through a special viewer.

Earlier than that, of course, there were the paired pictures on a card that were viewed through a twin-lensed instrument called a stereopticon.

You can still find the cards at flea markets, selling for as little as a dime apiece, but the stereopticon to view them is a pricey item at antique stores or auctions.

3-D movies came and went in the 1950s. The current fad is to let your eyes drift out of focus (actually, into individual parallel focus, rather than converging focus) until a seemingly meaningless pattern comes together in a crude and sometimes hard-to-discern 3-D representation.

Some stereo photographers make their own 3-D pictures. Some still use the old Stereo Realist cameras, but put up with long waits for processing by mail to get back paired slides that need a special viewer to be seen. It's possible, for those with deep pockets, to have a couple of Hasselblads joined into a single two-lensed camera. And who even wants to remember the ill-fated Nimslo or its hyperexpensive descendant Nishika, those odd four-eyed cameras with their approximately three-dimensional representations in print form?

Well, guess what? Now you can view your own snapshots in three-dimensional splendor, without it costing you an arm and a leg, and without waiting weeks for your pictures to come back from a special processor.

The first step is to buy two identical single use cameras and tape them together, end to end. Get the smallest, simplest cardboard cameras you can; no fancy panoramic, underwater, or flash jobs. Next, go out and snap the pictures of your choice, pressing both buttons as simultaneously as you can manage.

After you've shot all the film in your two taped-together cameras, mark one R and the other L (for right and left, of course). Separate them, and take them to your processor for developing and printing. It helps to make sure they get processed as two separate orders. I have my stuff done under the fictional names of Ralph and Larry, just to avoid strange looks and long explanations. Make sure they are processed as 311 prints, that is, 3-1/2 by 5-inches.

When they come back to you, keep the Ralphs and Larrys in separate stacks and lightly label the back of each print with an R or L. Find the element of either the right or left picture that is most in the foreground, and measure from that element to either right or left edge. Then, make sure the same foreground element is the same distance from the corresponding edge in the other photo. If there's a difference, eliminate it by trimming the photo with more. Now, stack the two photos so that the foreground element in each is superimposed, and use a paper cutter to cut the most interesting 3-1/2-inch square out of the stacked prints. This will give you two very similar pictures, but you'll notice a slightly different vantage point between the two. Remember, they were taken from points 3-1/2 to 4 inches apart from each other by the two cameras taped end-to-end.

Now, mount the two squares butted side-by-side (double-sided tape works well here) on a 3-1/2 by 7-inch card. Make sure the L print is on the left and the R print is on the right. Don't mix them up unless you want mind-expanding results that the artist M.C. Escher might have appreciated. You can view your paired cards in either of two ways. First, if you have been successful at seeing the hidden 3-D images in patterns such as those published in Magic Eye and similar books, you can look at these in exactly the same way. The other, somewhat more equipment-intensive way is to use an old stereopticon card viewer, or the functional equivalent. Looking through a viewer will give you the added effect of magnifying your picture, but either way you'll be amazed at the depth and reality of your snapshot.

A couple of tips and caveats here:

* Don't use single-use flash cameras for people pictures. If you're coordinated enough to press the buttons at exactly the same time (and almost no one is), you'll get twice as much light as you need and you'll wind up with overexposed pictures. If you're like the rest of us, and push the two buttons a fraction of a second apart, your subject will have blinked his or her eyes shut for the second exposure. And don't try to solve that problem by using one flash camera and one non-flash, because that will give you two pictures with vastly different exposures. Remember, the object is to get two nearly equal exposures from slightly different perspectives, just as your eyes register the images.

* Try to choose subjects that aren't moving, because if you fail to press the two buttons exactly at the same time you'll get two mismatched images that your brain won't know how to combine into a single clear 3-D image.

* Shoot only horizontal format pictures. Unless you're built a tad differently than the rest of us, your eyes are placed more or less horizontally in your head, just like the lenses in the two cameras you taped together, and that's how they perceive their two separate images.

* Try to hold the joined cameras steady and horizontal, so you don't wind up with one clear and one blurred picture, or one picture taken from a slightly higher point than the other. Until you get the hang of this, brace your elbows or the camera on a stationary object such as a fence, a wall, or the hood of a Car.

* Keep the closest element in the foreground about 10 feet away. A stereo photographer's rule of thumb is that the most realistic 3-D effect happens when the distance to the foreground is about 30 times the distance between the two lenses. The two lenses of taped-together single use cameras will be about four inches apart, so you should keep the foreground 120 inches away. Since these single users have fixed focus lenses for everything from four feet to infinity, that shouldn't be a problem.

* Look for scenes that emphasize depth, with clearly differentiated foregrounds, middlegrounds, and backgrounds. If you take a picture of a beautiful but distant scenic mountain range, you'll wind up with two nearly identical two-dimensional pictures--which will combine into one 2-D picture, a pretty but very flat effect.

* Don't be afraid of shooting scenes that violate important rules of composition for good two-dimensional photography.

"Flat" lighting should not be a concern. The depth in your picture comes from the depth in the original scene, not from the interplay between shadow and light. So shoot anything appropriate to the ISO 400 film these single-users contain. If you do shoot in bright sun, keep it to your back; as usual, try to avoid overly contrasty situations that won't reproduce well without custom printing.

Don't worry about the primary subject merging with the background. Even if it's the same color and similar texture, the 3-D will make it stand out when you view it.

Further, don't be bothered by dappling that occurs when sunlight filters through leaves. A picture of a piece of park sculpture taken under these conditions and printed in two dimensions will be virtually unreadable. But 3-D captures the depth regardless of the light; thus the same picture can be quite interesting.

A crowd scene usually has no central point of interest, no matter how spirited you think it is when you're part of the crowd. But snap it in 3-D, and you're part of the crowd again when you look at it. A dull picture fairly described as a composition disaster can become an endlessly fascinating photograph in 3-D.

And who hasn't been embarrassed to discover people with telephone poles growing out of their heads after the pictures come back from the processor? With 3-D, you don't have to worry about that, because the depth effect in the picture will separate the person from the pole. Unless, of course, you have a friend who really does have a telephone pole growing out of his head, in which case you may have to tuck a chain saw in your camera bag.

Even if you don't want to use cardboard cameras, you can still take 3-D pictures with a single camera that you already own. The only limitation is that you have to take pictures of subjects that don't move, so that you can snap both sides in succession rather than simultaneously. It helps to use a tripod with a device called a "slide bar" so you can keep your camera on the same horizontal plane as you move it from side to side. Beware of landscapes--they may seem like they don't move, but grasses, leaves, clouds, smoke and flags will all move in the slightest breeze, and your two pictures won't match.

The "rule of thumb" for proper stereo separation is that the nearest meaningful element in the foreground should be about 30 times as far away from the film plane as the distance between the centers of the two lens positions. Using that rule, the camera was moved over about 20 feet for the shot of the Lexington Avenue.

As in any photography there are rules of composition which generally provide a more pleasing result, according to people who claim to know. For example, strict stereo judges weep and wail and gnash their teeth when they see an object sticking through the "stereo window." Others (myself included) see exciting pictorial possibilities in the "in your face" attitude of some pictures that violate the rules. Follow your own aesthetic path. This "through-the-window" phenomenon happens, by the way, when the foreground element is less than 30 times the interocular distance.

Viewers are available from several sources. You can get an easy-to-assemble kit to build a cardboard replica of the old-fashioned stereopticon for around $30 from Van Cort Instruments, Inc.; Northampton, Massachusetts. Much more convenient to carry around, cheaper, and not as sharp, is a small lorgnette-type viewer available from Reel 3-D, Culver City, California.

Many people find they are able to train their eyes to "free view" a stereo shot. The trick is to see the two pictures in parallel, isolating each side to the appropriate eye. Ultimately, if you are successful, you will see a triptych with the center image being the one in three dimensions. For "training wheels" you might try either of the following approaches:

* Make a dot about 1/8 inch over the center of the top edge of each of the two sides, making sure that both dots are on an imaginary horizontal line. Gaze in as "spacey" a way as you can, until the two dots merge into one. Then allow your gaze to shift to the image area. You will see it in 3-D.

* Cut a piece of cardboard as long as your comfortable reading distance. Cut out a notch at one end to accommodate your nose. Hold the cardboard extending from your face, and hold the stereo view card perpendicularly at the end of the cardboard. The idea is to create a "septum" to make it physically impossible for your right eye to see the left image, and vice versa.

Another alternative, of course, is slide projection. For that, however, you need to be more equipment intensive, with two projectors, polarizing lens filters, and polarizing glasses for all your viewers.

Whatever method you choose, 3-D can be a delightfully satisfying way to break out of the photographic mold.

COPYRIGHT 1999 Photographic Society of America, Inc.
COPYRIGHT 2004 Gale Group