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SynthEyes has two main places to deal with distortion: early, before tracking, in the image preprocessor subsystem; and later, during solving. Each approach has its own pros and cons.
The early approach, in image prep, is controlled from the Lens tab of the image preprocessor dialog. It lets you set distortion coefficients to remove the distortion from the source imagery (or later add it). The distortion is removed before it reaches the trackers, the camera view, and the perspective view. But you must already know the coefficients, or fiddle to find them.
The image preprocessor can also accept lens presets, if you have calibrated the lens or obtained a preset elsewhere. The presets can specify fish-eye lenses or other complex distortion patterns.
The late approach to lens distortion, controlled by the main Lens panel and Advanced Lens Controls panels ("more" button), allows the solving engine to (optionally) estimate distortion values.
If the distortion is mild, you can have SynthEyes compute solely a quadratic distortion value. For larger distortions, it can calculate cubic and quartic distortions. Or more complex lens models can be selected, including for anamorphic distortion.
Note : When cubic, quartic, or more advanced lens distortion values are present, meshes will take longer to display in the camera view..
Tip : The camera view shows 3D positions and meshes distorted by the solver distortion outputs to match the original footage (at least, what is coming out of the image preprocessor). In contrast, the perspective view undistorts the original footage with the solver distortion outputs, so that the image matches the true linear perspective view.
You should always use the minimum distortion complexity possible , ie you should never turn on more complex distortion calculations than necessary, as doing so will destabilize the solve and produce deceptive over-fitting which shows lower errors, but actually increases errors when inserting 3D elements (see Using Zero-Weighted Trackers as Canaries).
Warning : Not all combinations of lens distortion types can be exported to all downstream applications, due to limited or incompatible features there. In some cases, STmaps/UVmaps can be used; for animated distortion that may mean entire sequences of maps.
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