SETUP YOUR PANORAMIC HEAD TO COMPENSATE FOR PARALLAX.

Etymologically, parallax comes from the Greek word "parallaxis", which means a displacement
from the Greek word "para", which means "next to"
from the Greek word "allaxai", which means "change"

Parallax occurs when the position of the observer changes while observing an object.

These images from Arnaud Frich show examples of parallax. The lens pupil shifts to the right when one turns the camera and the perspective changes. The alignment of the objects in the first and the second images is no longer the same.

This effect is similar to that which occurs when you place your index finger in front of your axis of vision and then close alternatively each one of your eyes. Your index finger appears to change position, or “move” in relation to the background.

In photography, this shift is observed in the camera’s viewfinder when the first and second shot are misaligned when rotating the camera. This is the “Variation", which exists between the camera’s mechanical rotation axis and the lens'pupil. If both the camera’s mechanical rotation axis and the lens'pupil were perfectly aligned, there would be no parallax at all.

For simplicity, we will refer to the lens' pupil as the point on which the rotation axis should be set to avoid parallax. The lens' pupil is located in the iris diaphragm of the shot.

When zooming, the lens' pupil moves according to the focal distance. Markers are necessary to determine the lens' pupil at each focal distance.