Is there a pendulum expert in the house?
08-28-2003, 11:19 AM
#11
Join Date: Feb 2003
Location: Florence AL USA
Posts: 53
RE: Is there a pendulum expert in the house?
I was trying to point out that it' s simply not possible to hit EXACTLY where the pin is at any distance and any height. If you use one of these, you have to be comfortable with an " acceptable amount of miss" . Obviously, that " miss" could still easily fall within the vitals of a deer.
I don' t have anything against the pendulum sights. I' m sure I have as much or more error in my " one fixed pin" setup, since I try to use it for everything from 0-35 yards. (By " holding over" at longer distances, etc.)
I just take exception with the hype that implies that these sights will allow someone to shoot X' s by using the same point of aim at any target distance/angle.
I don' t have anything against the pendulum sights. I' m sure I have as much or more error in my " one fixed pin" setup, since I try to use it for everything from 0-35 yards. (By " holding over" at longer distances, etc.)
I just take exception with the hype that implies that these sights will allow someone to shoot X' s by using the same point of aim at any target distance/angle.
08-28-2003, 11:33 AM
#12
Nontypical Buck
Thread Starter
Join Date: Feb 2003
Location:
Posts: 2,994
RE: Is there a pendulum expert in the house?
I was trying to point out that it' s simply not possible to hit EXACTLY where the pin is at any distance and any height.
Go higher or lower up a tree, the pin swings based on your new holding angle. Aim closer or farther out, the pin swings.
I was under the understanding that the advertised pin point accuracy was based on sound geometric principals, and my own experience correlates with it. Stay within the distance parameters, and you get the advertised performance, with the most likely problems coming from shooting severely up or down hill, but again this can be avoided if you factor them into the shots you take.
I' m not trying to argue, just I' m no mathmatician by any stretch of the imagination. Hell, it doesn' t even look like I can spell it
08-28-2003, 01:07 PM
#13
Join Date: Feb 2003
Location: Florence AL USA
Posts: 53
RE: Is there a pendulum expert in the house?
Range,
It’s not a matter of sound geometry, there’s also a large portion of physics thrown in. Let me say again, I think where we differ is in our definition of how this sight “works”. In other words, I would argue that your definition of “pinpoint” accuracy (and the definition used by advertisements) does not agree with MY definition. I would suggest that we’re talking in terms of inches and not fractions of inches.
Could you expound upon your “experiences”? Are these at shooting game, where you haven’t lost a deer yet, or are they at shooting precise targets, where you can judge how far your arrow impacted from the point where your pin was when the bow fired?
Let me re-state my other post, using the parameters that I have to stay within:
First shot (longest/highest allowed): 30 feet high, 90 feet distant (30 yards)
Second shot (from lowest practical treestand ht): 12 feet high
Using geometry, I can calculate that the angle you have to point the bow BELOW horizontal for the First shot is roughly 25 degrees. (This means that the pendulum sight has swung out 25 degrees and has achieved a specific position in the sight window.)
Now, lets move ourselves to the second height, 12 feet. We duplicate the exact same angle as the First shot, 25 degrees below horizontal. The pin swings back to the SAME position in the sight window as on the First shot.
Please note that since the angle is the same, the pin location is the same, so in essence this is the equivalent of having a fixed pin located at that position. (i.e., we’re shooting with the pin swung to the same orientation on both shots.)
So, if I project a line of sight at 25 degrees below horizontal from the 12 foot treestand, I am now aiming at a point only 25.75 ft (8.5 yds) away from the base of the tree (instead of the 90 feet distant spot from 30 feet high.)
If you tell me that you will hit with “pinpoint accuracy” a target placed anywhere between 8.5 and 30 yards using ONE FIXED PIN, then I’ll concede that the pendulum is pinpoint accurate. Personally, I’ve never seen a bow shoot fast enough to hit the exact same spot at both those distances. In fact, my rifle won’t even do it.
Like I said, my bow is fast enough that I use only one pin out to 35 yards or so. BUT, I know that I can’t aim at the X of the bulleye at all distances between 0 and 35. If I did, I would miss by some margin (high or low) except at one distance where my pin is actually sighted in (for me, somewhere around 25 yards.)
Hopefully, I’ve cleared up what I’m trying to say: the claims of “dead on” at every distance are misleading. Even though I’ve never had a pendulum, I can’t say that I wouldn’t use one or wouldn’t like to have one. I just believe that it needs to be used with the knowledge of shot trajectory that comes with using a fixed sight, and that the archer shouldn’t believe that these sights overrule any of Newton’s laws.
It’s not a matter of sound geometry, there’s also a large portion of physics thrown in. Let me say again, I think where we differ is in our definition of how this sight “works”. In other words, I would argue that your definition of “pinpoint” accuracy (and the definition used by advertisements) does not agree with MY definition. I would suggest that we’re talking in terms of inches and not fractions of inches.
Could you expound upon your “experiences”? Are these at shooting game, where you haven’t lost a deer yet, or are they at shooting precise targets, where you can judge how far your arrow impacted from the point where your pin was when the bow fired?
Let me re-state my other post, using the parameters that I have to stay within:
First shot (longest/highest allowed): 30 feet high, 90 feet distant (30 yards)
Second shot (from lowest practical treestand ht): 12 feet high
Using geometry, I can calculate that the angle you have to point the bow BELOW horizontal for the First shot is roughly 25 degrees. (This means that the pendulum sight has swung out 25 degrees and has achieved a specific position in the sight window.)
Now, lets move ourselves to the second height, 12 feet. We duplicate the exact same angle as the First shot, 25 degrees below horizontal. The pin swings back to the SAME position in the sight window as on the First shot.
Please note that since the angle is the same, the pin location is the same, so in essence this is the equivalent of having a fixed pin located at that position. (i.e., we’re shooting with the pin swung to the same orientation on both shots.)
So, if I project a line of sight at 25 degrees below horizontal from the 12 foot treestand, I am now aiming at a point only 25.75 ft (8.5 yds) away from the base of the tree (instead of the 90 feet distant spot from 30 feet high.)
If you tell me that you will hit with “pinpoint accuracy” a target placed anywhere between 8.5 and 30 yards using ONE FIXED PIN, then I’ll concede that the pendulum is pinpoint accurate. Personally, I’ve never seen a bow shoot fast enough to hit the exact same spot at both those distances. In fact, my rifle won’t even do it.
Like I said, my bow is fast enough that I use only one pin out to 35 yards or so. BUT, I know that I can’t aim at the X of the bulleye at all distances between 0 and 35. If I did, I would miss by some margin (high or low) except at one distance where my pin is actually sighted in (for me, somewhere around 25 yards.)
Hopefully, I’ve cleared up what I’m trying to say: the claims of “dead on” at every distance are misleading. Even though I’ve never had a pendulum, I can’t say that I wouldn’t use one or wouldn’t like to have one. I just believe that it needs to be used with the knowledge of shot trajectory that comes with using a fixed sight, and that the archer shouldn’t believe that these sights overrule any of Newton’s laws.
08-28-2003, 02:14 PM
#14
Nontypical Buck
Thread Starter
Join Date: Feb 2003
Location:
Posts: 2,994
RE: Is there a pendulum expert in the house?
Ok, I see what your saying. But I' m wondering if somehow the pendulum is taking arrow trajectory into account, as we know arrows arc versus following a straight line...
I pulled up an arrow launch program I have. With it I can input arrow variables such as weight, length, fps, etc, sight in different pins, shoot at varying distances and track the trajectory, fps and ke at various ranges in 1 yard increments.
I configured it as close as possible to my current set up, " set" a pin to be dead on at 30, then shot it at 8 yards on level ground. It impacted almost one inch high. At that close of a target, the arrow was still rising to the line of sight, and the variables I couldn' t control as well as the assumptions you made (" roughly a 25* angle) could well account for why it didn' t impact dead on in this simulation.
Perhaps that' s where the geometry comes in? We' re shooting an arc, not a flat line, so I suspect that is what' s at work here, I don' t know.
In my experience, shooting at targets, the advertised claims hold true. I suppose the " pinpoint" is up to me, but I can get the same groups as I do on level ground simply by holding dead on and letting fly.
I chose a pendulum as I used to shoot 1 pin like you, but figured my tight groups would open up a bit when the heat is on as well as be suspect to how well I estimated the range, so the 4-5" kill zone I could effectively have by using one pin out to 35 yard (assuming I released dead on) could open up significantly. A pendulum gives me the potential to shrink the group back down, as it takes the range estimation out of the equation...
I wish I had a trajectory program that was more exact, as I suspect the arc of the arrow flight would show even points of impact at the 8.5 and 30 yards you referenced...
I pulled up an arrow launch program I have. With it I can input arrow variables such as weight, length, fps, etc, sight in different pins, shoot at varying distances and track the trajectory, fps and ke at various ranges in 1 yard increments.
I configured it as close as possible to my current set up, " set" a pin to be dead on at 30, then shot it at 8 yards on level ground. It impacted almost one inch high. At that close of a target, the arrow was still rising to the line of sight, and the variables I couldn' t control as well as the assumptions you made (" roughly a 25* angle) could well account for why it didn' t impact dead on in this simulation.
Perhaps that' s where the geometry comes in? We' re shooting an arc, not a flat line, so I suspect that is what' s at work here, I don' t know.
In my experience, shooting at targets, the advertised claims hold true. I suppose the " pinpoint" is up to me, but I can get the same groups as I do on level ground simply by holding dead on and letting fly.
I chose a pendulum as I used to shoot 1 pin like you, but figured my tight groups would open up a bit when the heat is on as well as be suspect to how well I estimated the range, so the 4-5" kill zone I could effectively have by using one pin out to 35 yard (assuming I released dead on) could open up significantly. A pendulum gives me the potential to shrink the group back down, as it takes the range estimation out of the equation...
I wish I had a trajectory program that was more exact, as I suspect the arc of the arrow flight would show even points of impact at the 8.5 and 30 yards you referenced...
