Range estimation device
01-27-2013 | 02:58 AM
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Spike
Joined: Jan 2013
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Range estimation device
Range Estimation Device
Here is a simple formula for range finding that I found on a photography web site. This is a distance estimating formula that I believe would be good for use in 3-D contest because while it does a good job of calculating for range it does not, I believe, constitute an illegal method of range finding.
The formula is:
I held a ruler with right hand at arms length, first closed my right eye, used only my left eye to align one end of the ruler with a line or an edge of an object, then close my left eye, open the right eye, I noticed that the line now aligned at a distance X to the right of the edge. I noticed that the further the object, the greater the displacement.
After some simple calculation I found that the image displacement X is given by the following formula :X =E*(D-A)/D; where E is separation of eyes D is object distance, A is arm's length.
For example let Eye separation =7 CM, Arm's length=60 CM ;
D=1 M X= 2.8 CM
D=1.2M X= 3.5 CM
D=1.5M X= 4.2 CM
D=1.7M X= 4.5 CM
D= 2M X= 4.9 CM
D=2.5M X= 5.3 CM
D= 3M X= 5.6 CM
D= 4M X= 6.0 CM
D= 5M X= 6.2 CM
D=10M X= 6.6 CM
D=20M X= 6.8 CM
I got this from http://photo.net/minox-camera-forum/003HEV to give credit to the author.
This is an interesting formula and I did a few measurements in my kitchen and determined it to be accurate, but requiring a little more work than the average archer wants to do in the field. Plus I don’t think I would sit down and do a bunch of figuring before I got up to shoot on a 3-D range.
So what I came up with is the paint stirrer. I took a paint stirrer and a 3-D white tail deer target at known distance. I began at 10 meters and went back to 50 meters. I held the stirrer at arm’s length and marked off the body at distances out to 50 meters. I put a mark at the top and bottom of the shoulder at each distance. I then got my drill index out and drilled holes between the marks. I ended up with a stick with a few holes in it I can hold up to a deer (or target) in the field and get a rough estimate of the range to the target or animal.
Now this is rough I know. I recommend a good laser in your kit as well, but in the event the weather affects your laser, or batteries go out, you still have a way to estimate a shot.
Also, I don’t think anyone would object to this in tournament rules.
I like to take my stick out and check out distances from my blind to possible shots I might make. This gives me something to do in the off season because I can just sit back and watch the deer and other animals around my feeder. I guess you have to be a little eat up with being out-of-doors to put that much time into drilling holes in a stick.
Here is a simple formula for range finding that I found on a photography web site. This is a distance estimating formula that I believe would be good for use in 3-D contest because while it does a good job of calculating for range it does not, I believe, constitute an illegal method of range finding.
The formula is:
I held a ruler with right hand at arms length, first closed my right eye, used only my left eye to align one end of the ruler with a line or an edge of an object, then close my left eye, open the right eye, I noticed that the line now aligned at a distance X to the right of the edge. I noticed that the further the object, the greater the displacement.
After some simple calculation I found that the image displacement X is given by the following formula :X =E*(D-A)/D; where E is separation of eyes D is object distance, A is arm's length.
For example let Eye separation =7 CM, Arm's length=60 CM ;
D=1 M X= 2.8 CM
D=1.2M X= 3.5 CM
D=1.5M X= 4.2 CM
D=1.7M X= 4.5 CM
D= 2M X= 4.9 CM
D=2.5M X= 5.3 CM
D= 3M X= 5.6 CM
D= 4M X= 6.0 CM
D= 5M X= 6.2 CM
D=10M X= 6.6 CM
D=20M X= 6.8 CM
I got this from http://photo.net/minox-camera-forum/003HEV to give credit to the author.
This is an interesting formula and I did a few measurements in my kitchen and determined it to be accurate, but requiring a little more work than the average archer wants to do in the field. Plus I don’t think I would sit down and do a bunch of figuring before I got up to shoot on a 3-D range.
So what I came up with is the paint stirrer. I took a paint stirrer and a 3-D white tail deer target at known distance. I began at 10 meters and went back to 50 meters. I held the stirrer at arm’s length and marked off the body at distances out to 50 meters. I put a mark at the top and bottom of the shoulder at each distance. I then got my drill index out and drilled holes between the marks. I ended up with a stick with a few holes in it I can hold up to a deer (or target) in the field and get a rough estimate of the range to the target or animal.
Now this is rough I know. I recommend a good laser in your kit as well, but in the event the weather affects your laser, or batteries go out, you still have a way to estimate a shot.
Also, I don’t think anyone would object to this in tournament rules.
I like to take my stick out and check out distances from my blind to possible shots I might make. This gives me something to do in the off season because I can just sit back and watch the deer and other animals around my feeder. I guess you have to be a little eat up with being out-of-doors to put that much time into drilling holes in a stick.
