Deer Leif,
RC uses lens distortion coefficients with respect to the unit size image.
image coordinate = camera calibration matrix * distortion ( model, X in camera coordinate system )
Therefore depending on a tool which you are using you should first recalculate coefficients to the unit size image.
Is there any recommended workflow to handle lens undistortion without relying on the automatic feature of RC?
You can switch lens/calibration mode to fixed and input your values. You can do this using XMP files automatically.
The easiest way to do that is to align few images, export XML (using export metadata) and to edit XMP files.
RC automatically loads XMP files with the same name as loaded image files, e.g. image01.jpg and image01.xmp.
Another option, if your camera / lens model is somewhat distinguished, is to edit sensors xml file and add entry which automatically assigns lens/calibration parameters for all images which contain this camera/lens model.
- Code:
We would rather rely on proper checkerboard lens grids.