When using a Leaf Aptus or Credo on the Cambo WideRS or DS, you may consider some additional software that Leaf has available, for optimising image quality.
For creating the Lens Color Calibration Tool, Cambo also offers a special Opaque Perspex Plate, with a size small enough to carry with you to location, but large enough to guarantee a uniform opaque area to create the Custom White, to place in front of the lens while holding it with a handgrip, no need for screwing it into the lens front.