Re: range estimation help
I assume you mean IPHY (Inches per hundred yards), not "IDHY"?
Inches of target (height or width) / 'IPHY' reading * 100 = range in yards
For example:
15" tall target to you appears 4.5 'IPHY' tall.
15/4.5*100= 333 yd
It's a simpler MOA (1.047" per hundred yards) formula. Using a true "MOA" reticle, the object would be 4.3 MOA tall because 1 MOA is slightly bigger than 1 IPHY.
The MOA formula would be:
15/4.3/1.047 * 100= 333
Long story short, 1 MOA is a just a cunt-hair bigger "pie slice" than the "IPHY MOA".