What constitutes a stereo image? The normal, single
photographic image is called a “monocular” image since it stands by itself. The
term “stereo” means two and is considered a “binocular” set of images. The
stereo camera takes these two images simultaneously using two lenses. The
images are spaced roughly the same distance as our “interocular” distance, the
spacing between our eyes. Using a “Holmes” style viewer (such as the antique
stereoscope) or small “lorgnette” glasses to view the stereo pairs brings the
views together where we are able to see 3D depth.
The compositional approach is different between a single
image photo and a stereo photo. In single image photography, the photographer
tries to avoid anything in front of the object such as a tree in front of a
building. An angle will be chosen to photograph the building directly, without
obstruction. This can be for artistry or documentary purposes. In stereo
photography, the stereographer looks for something in the foreground that
compliments the main object in the background so there is a visual, spatial cue
when the images are combined to show the depth in the image. This can be a
rock, tree limb or any object. In some images, the main object will be in the
foreground and the spatial cue object is framed behind. For maximum depth
perception, it is best if the foreground subject is fairly close to the camera
with the background object farther away. The realistic perception of depth is
called “immersion.” The more the viewer is immersed in the image, the more real
the perception.
No comments:
Post a Comment