User Manual

Enable Lens Parameter
When enabled, lens distortion parameters are exposed to help in correcting lens distortion
when solving.
 Refine Center Point: Normally disabled, camera lenses are normally centered in the
middle of the film gate but this may differ on some cameras For example, a cine camera
may be set up for Academy 1.85, which has a sound stripe on the left, and shooting
super35, the lens is offset to the right.
 Refine Lens Parameters: This will refine the lens distortion or curvature of the lens.
There tends to be larger distortion on wide angle cameras
NOTE: When solving for the camera’s motion path, a simulated lens is internally
created to model lens distortion in the source footage. This simulated lens model is
much simpler than real-world lenses but captures the lens distortion characteristics
important for getting an accurate camera solve. Two types of distortion are modeled
by Camera Tracker:
1 Radial Distortion: The strength of this type of distortion varies depending on the
distance from the center of the lens. Examples of this include pincushion, barrel, and
mustache distortion. Larger values correspond to larger lens curvatures. Modeling
radial distortion is especially important for wide angle lenses and fisheye lenses (which
will have a lot of distortion because they capture 180 degrees of an environment and
then optically squeeze it onto a flat rectangular sensor).
2 Tangential Distortion: This kind of distortion is produced when the camera’s imaging
sensor and physical lens are not parallel to each other. It tends to produce skew
distortions in the footage similar to distortions that can be produced by dragging the
corners of a corner pin within Fusion. This kind of distortion occurs in very cheap
consumer cameras and is practically non-existent in film cameras, DSLRs, and pretty
much any kind of camera used in film or broadcast. It is recommended that it be
left disabled.
Enable Lens Parameters
When disabled, the Camera Tracker does not do any lens curvature simulations. This is the
default setting and should remain disabled if there is a very low distortion lens or the lens
distortion has already been removed from the source clip. Activating the Enable Lens
Parameters checkbox determines which lens parameters will be modeled and solved for.
Parameters that are not enabled will be left at their default values. The following options are
available:
 Radial Quadratic: Model only Quadratic radial lens curvature, which is either barrel or
pincushion distortion. This is the most common type of distortion. Selecting this option
causes the low and high order distortion values to be solved for.
 Radial Quartic: Model only Quartic radial lens curvature, which combines barrel and
pincushion distortion. This causes the low and high order distortion values to be
solved for.
 Radial & Tangential: Model and solve for both radial and tangential distortion.
Tangential relates to misaligned elements in a lens.
 Division Quadratic: Provides a more accurate simulation of Quadratic radial lens
curvature. This causes the low and high order distortion values to be solved for.
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