1 in 60 rule
something intresting I came across: circumference of a circle=2xpixR
where pi = 3.14... aproximated to 3. hence read the above eq as 6xR
standing at the center of a circle with a radius of 60nm gives you a circumference of 360nm (6x60=360). a circle consists of 360 dgs.
thus at a dist of 60nm:1dg=1nm. at 30nm 1dg=0.5nm. at 120nm=2nm.it was clear as mud at first but then i got the drift....