# Cross Calibration Training Parameter

Cross Calibration Training parameters lies under Calibration category of Setup page.

This page only have one parameter to configure: Lens Distortion Model

Lens Distortion Mode

- Three Param Radial

  This model calibrates for nonlinear optical distortion and perspective distortion. When compared with PerspectiveAndRadialWarp, this mode adds additional coefficients that properly model the location of the optical center. This mode is recommended for lenses with minimal to moderate distortion, typically those with focal lengths greater than 6mm.

- SineTanLaw Projection

  This model calibrates for nonlinear optical distortion and perspective distortion. When compared with ThreeParamRadialWarp, this model uses a computation model that is appropriate for lenses with moderate to severe distortion, typically those with focal lengths less than 6mm.

- No Distortion

  This mode will model perspective distortion only; any nonlinear optical distortion is ignored. By comparing the residual error values produced using this computation mode with the residual error values from ThreeParamRadialWarp or SineTanLawProjectionWarp you can improve your understanding of the individual sources of residual error.