I've been wondering about the newer range finders and their use of ARC technology (compensates for upward and downward trajectory). I have an internal conflict that seem to go against what i've read about these devices. I'm somewhat of a math nerd, so bear with me while I set up the conflict i'm having.
Most folks know that if you shoot from a treestand, you'll almost always shoot high. Some say it's because the deer "string jumps" the arrow, or that the hunter doesn't bend at the waist thus changing his anchor point, but others say it's because of the geometry of the shot, which is where the ARC technology comes in. Most of these rangefinders say that you need to aim as if the target is shorter than the line of sight. WHY IS THIS?
Why I have a conflict with this statement is because of the pythagorean theorem. (Bear with me)
This geometry theorem states that the hypotenuse (longest side of a right angled triangle) can be determined by squaring the two other sides of a triangle, adding them together to arrive at a figure and then taking the square root of that figure. C squared = A squared + B squared. I'll illistrate for ease of understandablity. Let's assume the terrain is perfectly flat.
Imagine your 30 feet in the air, we'll call that side B of the triangle. Imagine a deer is standing 30 yards from the base of the tree you are in, well call that side A of the triangle. Side B, 30 feet is 10 yards. 10 squared is 100. Side A is 30 yards, 30 squared is 900. So assuming the pythagorean theorem, A squared + B squared = C squared. So to find out the distance from your tree stand to the deer (position C), you would add 900 + 100 = C squared. 1000= C squared, equals 31.623.
I've added a link for a visual aid on a right angle. http://www.basic-mathematics.com/pythag ... lator.html
This tells us that if a deer is 30 yards from the base of your tree, you are 30 feet (10 yards) up the tree, the line from your stand, 30 feet up, to the deer is 31.6 yards. If the tendancy is to shoot high, wouldn't that indicate that the distance must be shorter? I know that 1.6 yards isn't a huge deal for most archers, particuarly at 30 yards, however you get the point I'm trying to make. I'm assuming that shooting high must have something to do with gravity being less on a downward shot compared to a perfectly horizontal shot.
Does anyone have an explaination to the above. I'd appreciate any comments, but I'm looking for something somewhat scientific.