3D movies, Motivated Camera movement

Respecting the Spatiality of a scene in 3D movies:

It may sound obvious, but is often overlooked by film makers today, who have had decades of experience in 2D movie making, where “creating” depth in a scene with lighting, lenses and framing was one of the most important aspects of shooting a scene. In 2D it is even easy to “Cheat” depth.

However, all that changes when getting into stereoscopic (3D) film making. For example, one does not need a montage of different angles to represent the geography and depth of an environment in 3D, as would have been needed in 2D.

The picture in this article illustrates the point. The one thing that 3D excels at, is in recording and presenting the spatial depth of a scene.

Motivated Camera Placement in 3D scenes:

Look at the image above of the man sitting on the bench (click for larger). This is a rough previz story board done in the excellent previz software FrameForge 3D. Of interest to us is the Camera data at the bottom of each panel. It shows Camera height at 2.91 meters from the ground. Ignore the 6mm focal length as this would rarely be used. To create accurate S3D previz, we should start with as many physical measurement of the real world location as possible… but getting back on topic:

The Camera Height shows 2.91m – What is the Motivation for placing the Camera at 2.91 meters?

This is the first question to ask when recording a stereo 3d scene. It may well be that it’s nothing to do with the script, except to show an establishing shot of a train station with a man on a bench reading a newspaper. In this case it is ok to place the camera at this¬†arbitrary height.

However, what if the script reads as:

“The detective approaches a man sitting on a bench reading a document, and comes closer to have a glance at what the man is reading”. We should be aware that in Stereo 3D, the spatial dimensions of a scene are faithfully recorded and presented, so the 3d camera placement at 2.9m above ground would yield a POV of the detective approaching the man seated would also run the risk of seeming like the detective is a 3 meter tall man!

Things get further complicated if in an effort to preserve “stereo roundness” or for other reasons, the interaxial (camera spacing) leads to hyper stereo and thus “miniaturizes” the seated man, bench or the rest of the props in the scene.

Read the rest in the Book, “THINK in 3D” via Amazon: Paperback & e-book (also on iPad via free kindle app)