Those new rangefinders are exaggerated in their adds for a bowhunting circumstance, rarely if ever will more than a yard or two difference and that is only if you hunt very high on a very steep hill.

A friend of mine wrote an article and tried to have it published, he included a chart from 18 and 21 feet, I'll show the chart for 21 feet in the tree.

Ranged Distance from Stand Actual Distance to Target

20 yards 18.72 yards
25 yards 24 yards
30 yards 29.17 yards
35 yards 34.29 yards
40 yards 39.38 yards

As you can see from his findings unless you hunt 60 feet in a tree and have an animal downhill 8 yards away you won't see a difference really. Those graphs they show you for advertising are entirely incorrect.