OPTICAL DISTORTION - IMPLEMENTATION
We will not take a look at undistortion just yet. However, to implement optical distortion within Nuke is quite simple with the help of the LensDistortion Node. For barrel distortion, setting a positive value to the 'Denominator s' knob field should do (e.g. 0.13), while for pincushion distortion, a negative value will yield the desired result. Mustache distortion might require specific values, which are: -0.4 in the first field of the 'Denominator s' and 0.25 in the second field. If we are applying any transformation or reformatting after or before the lens distortion, it is recommended to apply all the changes to a UV map and then apply everything at once using an STMap Node, to avoid filtering the input at multiple stages (for example, the LensDistortion Node only concatenates upstream).
