Quote from website :
The readings at 10 lines per millimeter measure the lens's contrast ability (red lines), repeating fine parallel lines spaced at 30 lines per millimeter measure the lens' sharpness ability (green lines), when the aperture is wide open.
Fine repeating line sets are created parallel to a diagonal line running from corner to corner of the frame, are called Sagittal lines (S)
Bros, able to elaborate the red ones i highlighted?
jsprtan also said 1 of the line is F8, the website did not state F8 . . :dunno:
What is image height from 0 to 20mm ?
So as website says 1 is the higest value for contrast, does the Y axis ( Vertical line) show for sharpness too ?