Nikon 18-55mm Lens Breathing & Tracking Challenges

With the Nikon D3200 18-55mm lens, lens breathing is clearly visible at sample focal lengths (18mm, 34mm, and 55mm). You can notice significant changes in composition when the focus distance changes.

This behavior makes camera tracking much more difficult because the solver must account for the focus distance in addition to the focal length to define a correct, undistorted perspective.

Lens breathing effectively influences the distortion grid even at a fixed focal length.

In theory, when solving a zoom/focus curve in a shot, you should consider lens distortion as a function driven by two variables: focal length and focus distance (excluding other parametric offsets like optical center offset). The problem is that in most tracking situations you don't have access to the actual focus distance data.

During a shoot, you must hope that the focus point isn't constantly shifting, or at least that you have custom lens distortion profiles at multiple focus distances.

Below are the focus shift comparisons for 18mm, 34mm, and 55mm:

18mm Focus Breathing:

34mm Focus Breathing:

55mm Focus Breathing: