Why a Shaft That Points At the Top or Outside the Ball on the Downswing is "On Plane"

[iacas]

In a word: parallax.

But let me back up in case you didn't read the title.

@mvmac and I will often tell people that we want the shaft to be pointing just outside the golf ball during the downswing, particularly when the shaft is vertical (from the face-on view) or roughly the A5 position - when the lead arm is parallel to the ground (horizontal).

Here's an example (sorry @nevets88 ! :D) of a shaft pointing pretty close to the golf ball at just past A5.

On the right, you'll notice three more lines. The center one is vertical. It doesn't have any tilt left or right. You can see here that Steven's camera was positioned a little inside his toe line, which makes his toes appear to be pointing to the right. The club parallel to his feet and his target line appears to be slanted to the left.

They're both going toward the vanishing point.

You've heard idea of train tracks, right? You know they'll never intersect, but to our eyes - and for this purpose to the "eye" in the camera, they do. They intersect at the vanishing point.

Here I've drawn the lines in that are parallel to Steven's feet and his target line. They're parallel, but due to the fact that we're viewing from a single point (the lens or sensor of the camera), they appear to converge (left image):

If you think that angle is extreme, consider where the horizon is (vanishing points exist on the horizon at our eye level) and consider the angle of the right edge of the mat.

On the right, above, I've illustrated how far behind the ball the butt of the club is at about A5. It's outside the back foot.

Consider the baseline of the plane. Though the clubhead or sweetspot are only on the baseline for an instant, they're on the plane the whole time. A club shaft that's on plane at A5 points straight down that plane (consider Hogan's piece of glass if you wish)… so where is the butt of the club pointing at A5?

Consider that the from the camera's viewpoint, it's compressing 3D into 2D, and it has a single viewpoint.

On the left, I've drawn a dot where the club shaft is actually pointing in this position. Remember, it's not pointing at the ground by the ball - it's behind his foot slightly. On the right, I've drawn the target line in green. You can see how this means Steven's shaft is too steep - it's inside the target line.

We're effectively looking at the "underside" of the plane here with a camera position along the toe line (which is again not quite where this camera is positioned).

I filmed a short video that demonstrates this "live."

Again, the closer the camera is to you, and the wider the distance between the ball and your toe line (or your ball and the camera angle), the more exaggerated this will be.

P.S. Steven's example is not at all "bad." There are lots of worse examples I could have chosen. I chose Steven's because I knew he wouldn't mind.

[mvmac]

Good demonstration Erik, thanks for posting.

[GolfLug]

In a word: parallax.

But let me back up in case you didn't read the title.

@mvmac  and I will often tell people that we want the shaft to be pointing just outside the golf ball during the downswing, particularly when the shaft is vertical (from the face-on view) or roughly the A5 position - when the lead arm is parallel to the ground (horizontal).

Here's an example (sorry @nevets88! :D) of a shaft pointing pretty close to the golf ball at just past A5.

On the right, you'll notice three more lines. The center one is vertical. It doesn't have any tilt left or right. You can see here that Steven's camera was positioned a little inside his toe line, which makes his toes appear to be pointing to the right. The club parallel to his feet and his target line appears to be slanted to the left.

They're both going toward the vanishing point.

You've heard idea of train tracks, right? You know they'll never intersect, but to our eyes - and for this purpose to the "eye" in the camera, they do. They intersect at the vanishing point.

Here I've drawn the lines in that are parallel to Steven's feet and his target line. They're parallel, but due to the fact that we're viewing from a single point (the lens or sensor of the camera), they appear to converge (left image):

If you think that angle is extreme, consider where the horizon is (vanishing points exist on the horizon at our eye level) and consider the angle of the right edge of the mat.

On the right, above, I've illustrated how far behind the ball the butt of the club is at about A5. It's outside the back foot.

Consider the baseline of the plane. Though the clubhead or sweetspot are only on the baseline for an instant, they're on the plane the whole time. A club shaft that's on plane at A5 points straight down that plane (consider Hogan's piece of glass if you wish)… so where is the butt of the club pointing at A5?

Consider that the from the camera's viewpoint, it's compressing 3D into 2D, and it has a single viewpoint.

On the left, I've drawn a dot where the club shaft is actually pointing in this position. Remember, it's not pointing at the ground by the ball - it's behind his foot slightly. On the right, I've drawn the target line in green. You can see how this means Steven's shaft is too steep - it's inside the target line.

We're effectively looking at the "underside" of the plane here with a camera position along the toe line (which is again not quite where this camera is positioned).

Thanks for the explanation Erik. Some confirmation for me here. Swing plane seems to be more of a swing 'band' around the torso below the sternum at a tilt which is flatter than nevet88's (hence club pointing outside of the ball at A5 as you explained) example which is what I try to use as a swing image. Because of my jacked up address I lift the club above this plane (backswing) and drop down on it to engage the torso and then begin the downswing. For whatever reason the image of Hogan's glass is not good for me (even if on plane) because it has always resulted in me trying to swing the club around the neck and felt handsy and overly vertical. Maybe works for other folks but really like what you have explained here.

[nevets88]

Thanks for posting this @iacas . I don't mind at all, it's actually cool to get a detailed explanation of something I did. For those who use a camera, anything that helps us understand what's correct or not, points us what to look for is very helpful.

So getting down to brass tacks - when you get the shaft pointed at the top of the ball or outside, you're on plane which means you're attacking the ball from the inside, you get a shallow angle of attack, gives you a better chance getting more distance and consistency? Plus Key #4 and #3?

[iacas]

So getting down to brass tacks - when you get the shaft pointed at the top of the ball or outside, you're on plane which means you're attacking the ball from the inside, you get a shallow angle of attack, gives you a better chance getting more distance and consistency? Plus Key #4 and #3?

When the sweetspot is on the plane early you can spend your energy and time delivering it down that plane, without compensations. Consider that the golf ball is "on the plane" so in order to make contact we have to be on a plane that intersects with the golf ball, in the end, or we whiff.

You can be on the plane and have a steep or shallow AoA. This is mostly about efficiency and minimal compensations. Key #4 directly, and often that ties into the others, particularly #5.

[boogielicious]

@iacas ,

Would having the camera aimed at the hands at A6, instead of the toe line, be better for evaluating where the club head is with regards to the swing plane?  You would essentially have the camera on the swing plane.

[iacas]

Originally Posted by boogielicious

Would having the camera aimed at the hands at A6, instead of the toe line, be better for evaluating where the club head is with regards to the swing plane?  You would essentially have the camera on the swing plane.

That's basically where it ends up being. You're talking about a few inches. Not a lot of parallax in that and since the toe line (obviously not the exact toe line if someone flares their left foot but not their right, or something like that) is obvious at setup, you aren't guessing at where the hands will be.

So, for consistency AND ease AND the fact that the hands are basically right near there anyway… :)

[nevets88]

@iacas - Quick question. For the driver, or any shot that's tee'd up. Should the shaft point to the top/outside of the ball as well? Or a little lower?

[iacas]

@iacas - Quick question. For the driver, or any shot that's tee'd up. Should the shaft point to the top/outside of the ball as well? Or a little lower?

Why?

Everything basically comes down to the viewing angles: how close the camera is, how shallow the swing plane is, where the camera and ball are positioned, etc.

If you can trace the target line back and have a general idea where the shaft is pointing, that's the main concern. For example:

The thing is, this also demonstrates that when we think the shaft is vertical really matters. I could advance or reverse any of these a few frames and get very different pictures.

So on some level, you're better off just going for some consistency, and if you're close, consider that it's likely good enough. This discussion, despite the use of your images, is mainly to illustrate severe cases where the shaft is pointing down well inside the ball even after the shaft is probably "vertical."

(Vertical used here means vertical from the FO view. It'll obviously be tilted somewhat in any good player's downswing.)