No worries, Jeff. You fight your corner hard :salut: - but maybe I do sometimes wonder whether you ever say to yourself "do I need to be in this corner in the first place?" - :laughing9 . Still good quality if your are springbok!

Perhaps you could do thread (within the confines of your zone - not sure if the protected zone is to protect "you" from "us" or vica versa! :laughing9 - joke!)on camera artifact in golf :

1)Rolling shutters and skew
2)Any camera and parallax error
etc..maybe a few more ...maybe the represenation of the "target line" on DTL shots (use line on ground or vertical shaft in ground with camera behind it...there must be a number of varaitions) - certainly gets confusing for players who use closed footline and open / square shoulders.... where are they aiming! Then you add in a "plane line" with inherent parallax problems...it is a wonder that video is ever helpful !!:laughing9

How do the ultrafast cameras like the new Casios, EX-1 or 20 or whatever they are, which give 400-1000FPS do it?? Would love to know if you can find out. Putting those cameras and FPS in the right price bracket should lead to the clubface getting an accurate representation in the next few years of golf instruction. Bizhub for the masses:golf:

Endgame extends into overtime!
 

Yoda - seeing that you are at the end of the game, and my overactive mind has forced me into an overtime time period, I will address this post to other forum members who may be following this debate (game).

I have thought of another example.

Imagine five ice skaters skating on an ice rink while holding hands. Imagine that they travel at the same rate of speed in a straight line direction, so that they are all in a perfectly straight line. Imagine that they all stop exerting any active force to propel themselves forward, and that they are all coasting at the same speed.

Now imagine that that the ice skater at the one end of the line (which I will call the central end of the line) abruptly brakes to a sudden stop and then spins in a circle around the axis of his stationary feet. His extended arm will then spin around his axis of rotation and create a circle of rotation of a finite radius. His extended arm will exert a pull force on the second ice skater that will cause the second ice skater to passively rotate in a circle at roughly the same rpm as the first skater. This transmitted pull-force phenomenon will occur down the line of skaters. The fifth skater (last in line) will travel fastest and also transcribe a circle on the ice and that circle will have the greatest radius. If the fifth skater is traveling in a circle due to passive pulling forces, then there must be a centripetal force in play - even though the pulling force is essentially circular in nature. Not only is there a centripetal force in play, but the fundamental source of that centripetal force is the fact that the first skater's extended arm is traveling in a circular manner around the axis of rotation (the first skater's feet).

Jeff.

GBD

The "protective zone" is designed to protect you guys from my thinking (or lack of thought).

I may take your advice. I definitely plan to learn more about camera artifacts, and if I learn something useful, I will communicate my acquired "learning" in a new thread.

Jeff.

court tv
 

Court reporter:

"Ok, so the prosecution it would appear is in deliberation now. Its been nearly an hour now. We can only suspect that they are frantically researching this last evidence presented by Golfbulldog that suggests the artifact is not to blame , that the shaft is a snake, based on the type of shutter used in both pieces of photographic evidence".

"Im going to ask an interested spectator here and forum member a question"

"Mr O.B. Left whats your take on what your seen unfold here today"

Mr left:

"I frankly dont know what this is all has to do with the pivot center but it sure has been interesting, Mr Lance is no doubt seeing a rise in ratings and viewership is on the whole way up, crazy stuff"

Court reporter
"We've seen some people leave the courtroom though"

Mr Left:

"Yes , true some people who were at the front of the court made their way slowly to the back and then sort of slipped out the door. Some are merely watching the clock like a student praying for the class to end so they can bolt"

Court reporter:
"but on the whole viewership it would appear is up"

Mr left:

"yes for sure but we'll have to see whether this is a bubble or not remember this is still in its infancy this whole format and certainly some left when the defense and Yoda rested. They're minds are made up I guess.

Court reporter:
"there are suggestions that the whole thing would be better off in the LaB"

Mr.Left
" I wonder if Plato had to deal with these sorts of irritating "show me" kinds of seekers. What are we in Missouri or something"

Court reporter

" Or misery maybe" I will say this however Jeff, is a game combatant and has never to my knowledge attacked anyone in a personal manner"

Mr Left

"Yes I like the guy. Very intelligent and probably has a formal education in the sciences of some sort. Not sure what his motivation is but.. He can just abandon something and then on the other hand.......... if this was a chess game youd have to question the manner in which he defended his shaft flex thing with a restating of Newtonian Law, sort of like defending a trapped pawn with your kind and queen". Im a Yodian , personally.. Who knows where this will end and what it will eventually imply to my golf swing" Im excited! As for me, my interests are only practical. I just want to compress my balls a little better.

Court Reporter
"Yes and weve lost Mike O. He was always compressing your balls."

Mr left
"no comment". "Lets just say that we all miss Mike".

Court Reporter
"For the record then. What type of shutter does your camera have"

Mr Left:
"I dont wish to comment but my lawyer will be issuing a statement shortly about the nature of my cameras CMOS shutter and the Vipers mechanical shutter."

Court reporter
"Thank you MR Left we'll wait for that and for the next exciting move from Jeff."


And 3,2,1...............

Anyone? Anyone?
 

http://www.youtube.com/watch?v=0s-oG...eature=related

:eyes:

Ive seen this picture before and to be quite honest, it would be hard to play golf with that second picture. Lag is great don't get me wrong. But can he sustain the line there? I would rather hit the face in the same spot.

( Notice his hips at the topend )

If you took his DTL line view I would think his shaft gets way way under the hand plane baseline too soon, via looking at were his right arm is to his body. Garcia and Hogan ( Lynn Ill use you as well if you dont mind) dont do that , they don't have much baseline disruptions which is why they are who they are.

Jeff, you crack me up!

Merry Christmas :salut:

Image 1: This "whip lag" is quite normal.

A lot of good players have a "two burst" swing, where the shaft is seriously bent in this part of the swing, and where something similar happens around impact. It's related to lag pressure.

The combination of lag pressure excerted by right hand - and rope handling pull from the left arm - will put a significant amoung of Newtonian moment to the grip end of the club. (Force x length). And the work from this moment stresses and bends the shaft. And increase the clubhead sped as well. AND ENERGY IS STORED.

Image 2:

While it is biomechanical possible to maintain the clubhead speed through impact it is impossible to maintain the brute force moment from image 1 all the way through. And when the moment decreases , the shaft starts to release. And since the club is a highly resonant system with moderate inner damping, the club will now whip forward - as it does here. This is not an ideal occurence since it means that stored energy is released long before impact. It is kind of similar to the dreaded throwaway. But given how we are built it is perhaps unavoidable in a swing that starts hard and fast down.


Image 3:

Strange things may happen to the shaft at impact. But it seems to me like this player has a two-burst swing. That he was reloading the shaft. Or at least was trying to. But the forward bend of the bottom half of the shaft will work against his effort of adding an extra ooomph at impact.

All this shaft bending and releasing business is about stored energy. If the shaft doesn't fit the swing, chances are that the energy stored in the shaft is released at the wrong moment. Further, the s- shape of the shaft just before impact here suggests there's no chance that all the stored energy will be used to send the ball far away. The shaft seems to be loaded and unloaded at the same time at impact.

I believe this is the kind of image that proves that the shaft manufacturers still have an interesting challenge in securing a proper and controlled sequence of energy storage and release through the swing.

Other people have a "one burst" swing, where the moment applied at the club shaft increases gradually through impact. But we aren't able to load the shaft as much at impact and therefore the biggest shaft bends are usually seen in strokes like image 1-3 with a big wrist cock and aggressive down swing.

And then some people are using an almost pure rope handling technique throughout without any of these shaft loading bursts. In addition to the extensive shaft loading we see above, the rope is pulling the center of gravity. And since this isn't on the shaft axis it will cause shaft bend as well. In which case the mechanical properties of the shaft will have less influence on distance, but perhaps on direction.

The stiffness of the shaft has a profound influence of the timing of the shaft rebound. A stiff shaft will release faster than a whippy shaft, and every player that applies some moment to the shaft (lag pressure) at impact would want a shaft that releases in juust the right moment.

Centripetal force only stores energy
 

I am not sure whether I understand everything that has been said about centripetal force & accelleration in this thread.

But there is one thing I know: Centripetal force doesn't produce swing speed. It only keeps it. It's an excellent energy storage device that enables us to keep what we have already put in there while we add some more....

But even a rope handling technique is more than centripetal force. We are not pulling our rope from the swing centre. We are pulling from a point that is forward of the swing centre (from left shoulder or left hand, depending on which part of the swing we look at).

The total force applied to the club at any point prior to impact can be decomposed in a radial (centripetal) component and a tangential component. And the little tangential force component has the same direction as the ball at - at least in an uncompensated swing. And that's the part that increases swing speed and adds energy to the swing.

PS:
I tried to post an illustration, but wasn't successful. Hope the text is clear without it.

CPwindow

I don't see how you can definitively conclude that his his clubshaft will get under the handplane in the later downswing. I can agree that he may have a problem with his pelvis outracing his upper torso and arms and that he may not be able to easily square the clubface, which will result in pushed shots.

I do not know the golfer personally. He merely wrote and stated that he tended to loss his lag on certain swings and he thought that it mainly occurred when he reverse pivoted.

I agree that having a large amount of lag (like him) is not necessarily advantageous if he cannot complete his swing on-plane in a perfectly synchronised manner.

Jeff.