[by Clyde DeSouza, realvision]

Excerpt:

The Camera Zoom in Stereoscopic 3D

In Stereoscopic 3D Cinematography, doing a zoom will “compress” or Flatten depth. This is due to the nature of telephoto (zoom lenses). You normally “dolly in” on a subject of interest rather than zoom-in in 3D, so as to avoid that layered or flat 3D effect also called “cardboarding”.

So called, because even though the scene looks 3D, it’s as if every layer of depth has been hand cut and placed into the scene.

Overscan, Re-Framing, and of shooting 3D images in Epic Proportions:

With the emergence of Large sensor Cameras and high resolution image acquisition formats such as 4k, 5K (Red Epic) and now even 8K cameras such as the Sony F65, there is much talk in some circles about “re-framing” after-the-fact when doing principal photography in movies both for 2D and 3D.

Such kind of re-framing talk does not sit well with every Cinematographer, many of who for decades have grown accustomed to “baking-in” the framing of a scene at the time of capture. But just as the “look” of a scene is no more baked in at the time of capture, in this digital age, with the use of LOG capture (in simple terms the whole dynamic range of the camera sensor is captured raw) and later used to create an infinite number of “looks” for color, contrast etc…

…so also should there be an open mind to the possibility of Framing for, or in this case, useful techniques can be crafted by capturing “overscan” imagery and then zooming in on the region of interest in a scene.

Principal Photography  in Stereoscopic 3D calls for rewriting of the “rules”

Infact in 3D cinematography, it is now an acceptable practice to frame a scene with a little extra “overscan” area. This assists the stereographer and editor in post production to sweeten or fine tune the depth budget of a scene and in some cases even save the scene from any overlooked stereo window violations.

Depth blending or Depth Ramping, the practice of bringing the outgoing scene and incoming scene to a comfortable viewing point for the audiences, between cuts in 3D, is also a time when shooting a bit of overscan saves the day.

…

Read the full, lengthy article here: http://realvision.ae/blog/2011/04/stereoscopic-3d-cinematography-zooming-in-3d/