range finder angle compensation

[gerald strine]

How important is the angle compensation feature on a range finder for tree stand usage? Has any one used these lets say I hunt 20 feet up and the shot is 20 yards how much difference in yardage is their?
If I buy a archery range finder with angle compensation they tend to be for under 100 yards not good if you hunt with a gun also .

[CDN Taxman]

A rangefinder should measure the distance of your shot without regard to how high you are.

Mike

[CDN Taxman]

This is a post from another forum that I had done.

You have to know the true distance from you to the target and use that yardage as your aiming point. No higher or lower required.

Remember the Pythagorean Theorem?



Modifying that formula, C, the distance you are shooting is equal to the square root of A^2 + B^2.

So, let's say the deer is 20 yards out and you are 12 ft (4 yards) up.

C = sq root of (20^2 + 4^4)
C = sq root (400 +16)
C= 20.4 yard shot

So, holding your 20 yard pin on the deer would likely result in a marginally lower hit than you were expecting.

Of course, a range finder would figure all this out for you in advance!

Mike

[Keating]

Mike, the issue is that the arrow will drop due to gravity over the horizontal distance the arrow travels.

in the example you present, When the shooter takes a reading with his range finder from 12' up in his treestand, the range finder will present a line of sight distance reading of 20.4 yards.

if you shoot for 20.4 yards, you'll shoot high as the arrow is only dropping over a horizontal distance of 20 yards.

The idea of a range finder with Angle compensation is that it automatically detects the angle the rangefinder is aiming down to the target (in degrees from the vertical), and uses the Sin of this angle and the point to point distance, C, to determine the horizontal distance to the target, B.

If your rangefinder does not have angle compensation, then your readings will always be "long". Now knowing your target is 0.4 yards closer than your rangerfinder reading, do you have a pin/reticle for 0.4 yards of compensation?
If not, Why bother spending the extra money on an Angle Compensating rangefinder?

Paul

[gerald strine]

that is exactly what my question is are the yardage difference big enough to matter at bow ranges vertical vs horizontal a 1/2 yard difference is not but the example given was only at 12 feet up what about being 20 feet up with sloping down terrain?
I am looking for some one who has a range finder that will will tell you the actual distance and the horizontal shot distance and how big of yardage variance is their from their hunting experiences.

[CDN Taxman]

The arrow is not travelling 20 yards but 20.4 yards (not a huge difference I'll agree). Gravity is still pulling on the arrow. I'm no scientist, but the effects are likely the same as if it was dropped straight from the stand at 9.8 mp^2.

Mike

[Keating]

The total distance the arrow travels is 20.4 yards.
Any rangefinder will mark the target as 20.4 yards, but the horizontal distance travelled is the distance we're concerned about. Hence a Rangefinder with Angle compensation will tell you to aim as per a 20 yard shot.

Think about it in the extreme opposite case. Your treestand is 50 feet up the tree and the deer is standing 5 feet from the bottom of the tree. pythagorean theorem will tell you the target is 50.25 feet, or 16.75 yards away.

do you aim for a 5 foot shot or a 16.75 yard shot?
gravity is perpenticular to the surface of the earth, not the path of the arrow, so there is less force acting on the arrow to lower it's path relative to your sights. it should be pretty clear that you shoot the 5 foot POA, and not the 16.75 yard.

The arrow is not travelling 20 yards but 20.4 yards (not a huge difference I'll agree). Gravity is still pulling on the arrow. I'm no scientist, but the effects are likely the same as if it was dropped straight from the stand at 9.8 mp^2.

Mike

[Woody Williams]

Are you guys that good of a shot that you can tell 20.4 yards from 20 yards?

POI change couldn't be an inch at most, if that.

Personally I think a angle compensation range finder would only good if you ar in some very hilly terrain and have some super steep up and down angles.

Other than that it is a waste of good money - IMHO..

[Keating]

Agreed.

in a flat area from a 15-20 ft tree stand, it wouldn't be useful until the shots were too far to make with an xbow anyway.

Personally I think a angle compensation range finder would only good if you ar in some very hilly terrain and have some super steep up and down angles.

Other than that it is a waste of good money - IMHO..

[Riflemanz]

I laser my target straight out to a tree that's near the deer i'm going to shoot.I never laser on a angle downward.

[Rich]

Gerald,

If you plan to just use it for bow hunting then the answer is "NO". I have sat in my tree stand for hours entertaining myself with my Leupold RX II. I normally sit between 22-24 feet high and I will range distances with the angle compensating mode and regular line of sight and what I have found is that there is normally less than 1 yard difference. If you were going to use it to rifle hunt in very steep terrain I could see it making a difference, but not for normal bow hunting ranges.

Rich

[wabi]

When I hunt from an elevated stand, I think *spherically* or in a three dimensional manner and not a two dimensional manner like I do while on the ground.

I try to do the same. Often (or should I say - usually) a high entry point puts the arrow through the vitals better than a low (proper from ground level) hit will.
So I don't worry about trajectory when in a stand. I sight my bow for 25 yards (good for a dead-on hold out to 30 yards +/- a yard or so depending on arrow speed) and just hold where I want the arrow to go (remembering the deer is a 3-D target and I want both lungs!).

With my sight-in 20 or 20.4 (or 8 or 18 or 28 for that matter) yards doesn't even concern me - from the ground or from a stand!
See deer, put the crosshair where I want the arrow to go, and a couple inches high or low doesn't really matter! Broadhead through both lungs = dead deer! (and a short tracking job to find it)

Edited to add:
Proof my system works for me!
2009 results from ground (a high hit because she was close, but still through both lungs!)-

09 doe.JPG

2009 results from a tree stand -

09 button buck.JPG

Both were short tracking jobs, I saw the doe go down and the button buck made it behind some brush, but was still very close. I went to where I last saw him as he ran off, and could see him down from there.

(Sorry if the blood in the pics offends anyone, but if it does perhaps you should take up knitting instead of hunting. If you hunt and don't see any blood, you probably aren't much of a success as a hunter. )

[Hoss]

When I hunt from an elevated stand, I think *spherically* or in a three dimensional manner and not a two dimensional manner like I do while on the ground.

OH GEEZ here we go Bob... I dont even no what that word means..lol (spherically) but it sounds good...