3D movies and Motivated Camera movement.
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.
In a 2D film, this is not so much of a concern as depth and perspective can be cheated. In Stereo 3D, a film maker has to step back, take a macro look at the scene and then decide on what the motivation is for a particular choice of camera placement.
The image above from the movie Drive Angry 3D, shows another side effect of un-motivated Camera placement; Perspective mismatch and Depth Continuity issues between this shot and the next.
Motivated Camera movement is Stereoscopic 3D:
The movie Hugo, has received well deserved acclaim for showcasing stereoscopic 3D as a new medium of visual storytelling. There is much to be learnt from the camera work and stereoscopy in the film.
Some observations from the 3D Trailer above:
0:30 – Notice the perspective, height and point of view as the camera tracks into the scene
0:43 – A perfect combination of interaxial setting (no miniaturization of the scene or king-kong effect) noticeable as the camera cranes up in the rise-up shot.
Careful orchestration of such a move (correct interaxial, timed cut, taking the proper amount of dwell time into consideration) will lead to compelling S3D Cinematography in scenes involving Jibs and Crane shots.
Motivation? if the actor in a scene was riding an elevator up or a Helicopter lifts off from a helipad with the actor looking down, this would be the added motivation for such camera moves in S3D! Ultimately the premise of Motivated Camera movement for effective stereoscopic 3D movie making is the choice of the Director and the DP.
To see how Crane and Jib shots could break the suspension of disbelief for audiences and pull them “out” of the scene, pay close attention to these scenes from:
1) Transformers: When the main actor comes out of his parents Mobile Home.
2) Drive Angry 3D: A high shot looking down on the gun fight in the motel room. – Side note: in S3D, bigger is better. So the screen size does save the scene to a certain extent from extreme miniaturization. A different choice of interaxial (lesser) and lens, would have made for a better 3D scene, should the Director have insisted that the camera needed to be placed up high for the shot.
This article is not a set of rules, but more a guide, aimed at seeding ideas as we move forward toward defining a new language and grammar for the art of stereoscopic 3D movie making.
