In this video, we will talk about the parallax error in panoramic photography.
In panoramic photography, the camera must be rotated around a virtual point in the lens, called the no-parallax point (or NPP), to avoid parallax errors in the stitched panorama.
Let's place two objects in front of the camera: one blue close to the camera, and one red farther away (the farther, the better), so if we look through the camera viewfinder, the objects appear centered.
If the camera is positioned correctly (that is, it rotates around the no-parallax point), when we tilt the camera the objects are still centered. The same goes for tilting the camera in the other direction.
If we slide the camera into a wrong position and then tilt it again, we will notice that the two objects are no longer centered.
That means one object in a photo, and two in the next. Therefore, these photos will be difficult to stitch. The same goes for tilting the camera in the opposite direction.
Now let's slide the camera back to the correct position - so that it rotates around the no-parallax point - and see a view from above.
By panning the camera to the right or to the left, we can see a perfect centering or overlapping of the two objects, regardless of the angle of rotation.
If we slide the upper assembly into a wrong position and then perform a panning to the right or to the left, we will see the two objects are no longer centered, indicating that the camera does not rotate around the no-parallax point.
So, just like before, if the no-parallax point is not set correctly, in panoramic photography a photo will not overlap perfectly with the next, resulting in stitching errors and ghosts, as in a photo there is one object, and in the next there are two.
In the MECHA's User Interface there is the NPP button that displays instructions for determining the NPP along the lens axis using camera live view. Also, for those interested in finding the no-parallax point, we put some useful links below.