>>42058962/2
lay the tape measure on the floor, the longer the better.
align the O camera symbol to the no. 0 of the tape measure.
check what distance numbers are on the lens then put corresponding small objects (small clock, small container, etc) as markers on the same distance on the side of the tape measure.
use the focus peaking on the tilt screen to check if the markings are accurate.
if not, remove the ring mount again and add another layer of paper ring.
test again with the tape measure.
if the focus goes off too much then you can cut one layer of paper ring and retain the paper on the screws to make the thickness 1/2 of the paper ring.
so its trial and error until the distance scale on the lens ring corresponds to the actual distance scale on the tape measure.
also test the infinity focus.
