Panning around the Entrance Pupil (Nodal Point)

[silvan schnelli]

Is it common as a cinematographer to try and position the optical system in a manner where the entrance pupil serves as the axis of rotation, in order to prevent parallax (change in perspective) during camera movements? Is this only used in VFX or would it in theory also improve the naturalism of panning camera movements in general?

[Daniel Klockenkemper]

In practice I doubt it's common at all.  The vast majority of camera support devices are balanced relative to the camera's center of gravity, which puts the nodal point of the lens forward of the pan axis.

Renting specialty equipment to balance the camera around the nodal point is not only an additional monetary cost, it also requires extra time to configure and re-configure when there are lens changes, etc.  It might create significant extra difficulties for certain camera operating styles (e.g. handheld).  When not strictly needed for VFX or technical purposes, I doubt many productions would feel the costs are justified.

To what degree nodal pan and tilt movements contribute to "naturalism" in storytelling is a separate and more subjective topic.  Certainly, human eyes rotate very closely to their nodal points; however, when people turn their entire heads the rotation is centered around the neck/spine, which puts the nodal points of the eyes far forward, similar to common camera supports.

I also feel that most of the time, camera movements are intentionally performed in order to change the perspective, so a minor offset in parallax would be seen as a benefit rather than a drawback, if it is even considered at all.

[silvan schnelli]

@Daniel Klockenkemper

Thank you for the great response.