The DEPTH Workflow - 3D Postproduction: Stereoscopic Workflows and Techniques - page 152

is violated. The reason for this is due to human physiology and evolution. In
this topic, we emphasize violations of the left and right frame edges as these
issues are far more likely to generate discomfort and discontinuity in viewers.
Edge violations are part of 3D imaging and do not always need to be i xed.
Edge violations may not be an issue for your show if:
• the object creating the edge violation is outside the area of interest
• the object appears only l eetingly and/or during motion
• you decide edge violations are not an issue
5.6.2.4a Solution 1: Re-Position/Re-frame
The simplest solution is to re-position/reframe the shot so that the object
straddling the edge no longer straddles the edge. If this does not address
the issue (or if you cannot reframe because you do not have the rest of the
image available for both eyes) there is a common solution called “l oating
windows.”
5.6.2.4b Solution 2: Floating Windows
Adjusting the left and right edges of the frame to the left and to the right
to mask the portion of the object seen only by one eye can alleviate the
“splitting” issue associated with edge violations. This is known as l oating
windows. Floating windows make sure that both of your eyes see a similar
portion of the object. With this technique, the left and right edges of the
frame are “l oated” in and out to the right and/or left. Floating windows
can also mask the offending object entirely. How you use l oating windows
will depend on your show and on the resources available to experiment
with various settings. The person in the Stereographer role can help you
determine which shots, if any, require a l oating window treatment.
5.6.2.5 Issue: Excessive Parallax
Parallax is a measurement of the disparity or horizontal separation between
L and R. The amount of parallax in a shot depends on the interaction between
the convergence angle and IA setting during image acquisition. What can be
changed in post is the relative distance between L and R.
Maximum Negative (Near) Parallax
Our eyes can only cross in front of us (converge) so far before the image
disintegrates and/or the effort to do so becomes uncomfortable (as in
nauseating). What this means is that there is a limit represented by a number