For accurate calculation of field of view (FoV) from using Imatest’s SFRplus, eSFR ISO, or Checkerboard, modules, it is critical to use proper distance measurements entered into in centimeters into the more settings window.
Lens to chart distance (in centimeters) can be best measured by a laser range finder.
For SFRplus it’s the bar to bar height is measured from the top of the top bar to the bottom of the bottom bar.
For eSFR ISO this is the vertical distance between the registration marks in centimeters.
Checkerboard uses the size of the squares.