RE: aim low hit high?
Gravity...............The aim low hit high from either a elevated or low position can be true. The gravity equation becomes more noticeable on longer bow shots or with rifle hunters particullary in mountain hunting.
when you are up in the stand 20+ feet and the animal by arrow flight is 30 yards it may only be from the base of your tree 20 yards. That 20 yards is your true distance according to gravity. If you use your 30 yard pin you will hit high.
This works the same way shooting uphill.
You are starting to see a lot of range finders anymore that will calculate your true ballistic distance based on grade. It does make a difference.