Nodal Point

What is it and how do I find it?

This is one of the most frequently asked questions when it comes to stitcher-based panorama creation.

Once you understand the basics, you’ll be able to easily locate the nodal point for any camera and lens combination.

Simply put, the nodal point is the point inside your camera where the light rays converge and flip over.When shooting a panorama it’s necessary to rotate about this point to eliminate the image mismatch caused by parallax error.

It’s also worth noting that the nodal point is not the same as the film plane, which is often marked on the underneath side of many 35mm cameras. Generally, for most 35mm cameras and lenses, the nodal point is located somewhere towards the center of the lens barrel.

Parallax error can be easily demonstrated by this simple experiment. Close one eye and hold your index finger upright about six inches away from your open eye. Rock your head from side to side. Notice how your finger moves with respect to the background.This relative movement is due to the fact

Parallax error can be easily demonstrated. It’s the relative move- ment caused by a shifting point of view. In this example, you eye is moving with respect to your hand and the background.

that you’re not rotating your head around your eye’s nodal point, which is somewhere in the center of your eyeball. Instead, you’re rotating about your spine which is several inches to the rear and off to one side. It is this relative side-to-side motion that we will strive to eliminate when setting up a camera for VR panoramas.

Step 1:The side-to-side adjustment

Once your camera is fastened to your camera bracket, move to the front of the tripod head so you’re looking into the lens.Adjust the camera bracket so that the center of the lens is directly over the pivot axis of the tripod head. Try to be as accurate as possible.You should strive to get this adjustment within plus/minus a 1/16th of an inch. Step 2: Fore-Aft Adjustment

This step is most easily accomplished out of doors. Find a vertical edge or line, such as a doorway or edge of a building. Position your camera and tripod about 2-1/2 feet away, or as close as possible with the edge still in focus when you look through the viewfinder.

Looking through the camera’s

10

Page 11
Image 11
Kaidan KiWi Panoramic Tripod Head manual Nodal Point, Side-to-side adjustment