All Things Color for Film and Digital Cinema
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Floating Windows

Floating Windows in 3D post

The use of Floating Windows can help aid 3D problematic sequences and shots where images with a negative parallax (forward of the screen) break the edges of the screen plane. These are called Window Violations.

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By manipulating the image boarders with masks one can help reduce the breaking of the immersive illusion. These masks can serve two purposes.

Firstly they can help reduce the curse of retinal rivalry where an object on the edge of screen is present in one eye and not the other.

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Secondly they can perceptually bring the screen plane forward or backward to become inline with an object of negative parralax that is breaking the screen edge.

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Depending on the camera or object motion through the shot the Floating Windows can be dynamically tracked to match.

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Unfortunately there is a bit of a problem with this function in the real world theatre though. I watched a 3D kids animation feature on the weekend and noted the projected image was (as usual) projecting into the theatre blacks surrounding the screen. (In 2D cinema we can usually use a TV like 10 percent safe area to imagine worst case scenario projection masking.) Because of this the floating windows of many shots became nulified as they shot into the blacks and therefor many shots broke the screen window somewhat uncomfortably that would have been otherwise fixed with this technique.

Additionally Floating Window effects are also masked due to keystoning of the projector itself. Most theatrical cinemas have their projector raised almost to the level of the top of the screen which naturally causes keystoning. The easy way out of this is to increase the theatre masking so that a true rectangle is projected. This will most definitely mask the Floating windows as well. Some distributors would prefer the image was left full frame in a trapezoid shape that included all floating windows.

Adrian