Shooting strictly parallel (for IMAX)

Shooting strictly parallel, without angulation or post-production shift, is a technique now only used for the IMAX format, where it is well adapted.

For all smaller screens (theater or TV), this technique is generally disappointing, since its main characteristic is the absence of positive parallaxes: when shooting strictly parallel, everything is in front of the screen, nothing is behind the screen - and the optical infinity is on the screen plane.

When shooting strictly parallel, we get only negative parallaxes – or 0% parallax, for objects at optical infinity.

On a screen smaller than an IMAX, this leads to Stereoscopic Window Violations: collisions between the objects supposed to be “in front” of the screen and the frame borders. These borders are out of your field of view in an IMAX, but are very visible on a smaller screen.

Moreover, out-of-screen effects are not very comfortable on a small screen, because the screen is closer to the spectator. On those screens, the eyes are forced to take a quite strong angle of convergence to fuse out-of-screen effects - which is very tiring, or even hardly possible for some people.