RE: Treestand compensating rangefinder
a²+b²=c²
If you are 21ft(7yds, a²) up in the tree and thedeer is 45ft(15yds, b²) from the tree then he will range at 49.5ft(16.5yds, c²). If the deer is 75ft(25yds, b²) from your tree he will range at 77.88ft(25.96yds, c²).
Wth the math you can see that the farther out the shot, the more accurate the rangefinder. You can also see that the rangefinder would never be more than 2yds off (as previously stated) unless you were higher than any tree I can get in. Bottomline for me though is that the distance from me to the deer is what the rangefinder states. Since my shots will not be longer than 25 yds any angle compensation is kind of useless. The nikon 440 works just great for me.