Guide to 3D Photography
This page describes a simple method of taking and viewing 3D photos that anybody can use. Anybody with one camera (any type) and two eyeballs - with no need for any special equipment, viewing devices or funny glasses.
The accompanying pages show examples of Australian and American scenes in 3D using this method. These pages are part of the Stereoscopic 3D Webring.
In a nutshell
When we look at something with our two eyes, we see in three dimensions because our brain interprets depth by comparing the two images from the left and right eyes. To simulate this photographically we need two photos of the same scene, taken from slightly different positions. This can be done using two cameras mounted together, or a multi-lens camera designed for stereo photography, but can also be done with just one camera - even the most basic type. Its simply a matter of taking one photo, moving the camera to one side, then taking another photo. Same scene, slightly different viewpoint.
The easiest and most flexible method of viewing the two photos is the "cross-eye" method, where the photos are placed side by side with the "left" photo on the right, and "right" photo on the left. By slightly crossing the eyes, each eye looks at the photo meant for it. When the images match up and focus, the scene appears in life-like 3D, or a good approximation of it. This method can be hard to learn for the first time, but once mastered it is really quite easy. One advantage of this method, apart from requiring no equipment for viewing, is that the photos can be any size. Big enlargements on a lounge room wall can be enjoyed in 3D from across the room.
Taking the photos
- Using any type of camera, take a photo in the normal way. Take extra care to keep the camera level, and remember what object is in the centre of the viewfinder.
- Move the camera to one side, position the same object in the centre of the viewfinder, and take the second photo.
- How far do you move the camera between photos? For close objects, about the distance between your eyes. For more distant objects, a greater separation is needed to give sufficient depth to the photos. A rough rule of thumb is to move the camera at least one thirtieth of the distance to the nearest significant object in the photo. If in doubt, experiment!
- The best results are given by scenes containing both near and distant objects, and preferably something in between - this gives a greater sense of depth. Things receding into the distance - such as roads, railway tracks, fences - can work well. Far-off scenery without a prominant foreground can look flat, even with wide camera separation.
The obvious drawback of this method is that moving objects will have moved between the taking of the first and second photos, making this method of 3-D photography unsuitable for action scenes. Thats why some 3-D enthusiasts mount two identical cameras together to enable simultaneous photos. However, movement from secondary objects like passing traffic, wind-blown trees or waves on a lake need not be a problem as long as the main content of the photo is stationary.
Car parked beside the Swan River in Perth.
(Click on photos to see larger version)
Viewing the photos
- Using the pictures above as an example, place your pair of photos side by side with the left view on the right, and the right view on the left. Ensure they are level with each other. A small gap between them can assist the viewing process.
- The distance from your eyes to the photos is not critical - whatever distance you normally sit from your computer screen should be fine. If you hold a finger in front of your face as close as you can while still being able to focus on it comfortably, then double this distance will be your minimum distance for viewing 3D photos.
- Begin to converge your eyes, ie. go cross-eyed, but do it slowly. At first you should see four photos in front of you - two images for each eye - but as you converge your eyes the middle two should line up. This is what we're after: three images, with the middle one consisting of the left and right images merged together.
- While keeping the two images merged, gradually bring them into focus. This is the tricky part! Normally when we look at something our eyes focus on whatever distance our lines of sight converge, but to view 3D with the cross-eye method we need to focus on photos that are twice as distant as the point our eyeballs are aimed at. This is not a natural skill, so it needs to be learned.
- If you normally wear glasses, wear them to view 3D photos as correct focus is necessary.
- Its important to keep your eyes and the photos horizontal so that the images line up properly. If they don't, try tilting your head slightly each way and see if that helps.
- Cross-eyed 3D viewing will feel unnatural at first. Have a rest if you feel any discomfort, as eyestrain can cause headaches.
If you managed to see in 3D - congratulations! If you didn't, I encourage you to be patient and keep trying. Once mastered, it becomes easy and comfortable, and literally opens up another dimension in photography. There are more photos to try viewing in my two other 3D galleries.
In either case, why not try taking your own 3D photos? Those displayed on computer monitors are restricted in their size and clarity, but real photos are easier to view in 3D, and give much more impressive results.