How to view side-by-side stereo images
There are many different ways to experience 3D images. One way that's been around forever is side-by-side stereo pairs. Side-by-side stereo pairs come in two flavors - parallel and cross-eyed. Generally speaking, parallel images are used when the viewer will be using some kind of viewing device - such as the old Victorian stereo postcard viewers. Cross-eyed images are better for free viewing - fusing the two images into one without some kind of viewing device.
The Free View Technique
The trick to Free Viewing is allowing your eyes to crossover at one point and focus on another. This is contrary to your natural viewing habit and why it's a little strange to do at first. Read through these instructions and try to view the images on the Stereo Sampler page.
|1 Place your finger near your monitor in the center of the image pair. This will focus and converge your eyes to the same position.
2 Slowly move your finger toward your eyes. Your eyes will accommodate (stay focused on your finger) as they increase their convergence ("toe in"). The image pair on your screen will begin to form a third image as they overlap. Slightly tilt your head from side to side as necessary to perfectly align the overlapping center image.
3 Now for the hard part. Keeping your eyes converged, lower your finger and try to shift your focus to the screen. The 3D effect will appear.
How it Looks On Your Screen
Ignoring all the clutter and concentrating on the overlapping image is key to the Free Viewing technique. It helps to maximize your browser window.
|1 Both your finger and the monitor's screen are in focus and your eyes are converged at the same position.
2 As you move your finger toward your head, a third image begins to form onscreen as the stereo image pair overlaps.
3 As you maintain your eyes' convergence point and shift your focus to the screen, the 3D effect appears in the central overlapped image.
Free viewing has the advantage of not requiring any special viewing devices. However, most people find it uncomfortable with time.