drakulie,
First, Here is a description of the frames in the picture:
FRAMES p1 to p4 are 4 consecutive framesof the toss as it is going up to
show the path of the ball.
FRAMES -2, -1, 0, 1, 2, 3, 4 are consecutive frames leading up to the
moment of impact and after it. Frame 0 is closest to where contact
occurs.
I'll provide a short gist of the analysis followed by a more detailed one
below to fully explain my analysis. I think what happened is that your
camera gave you 16 frames but what happened is that from the
small LCD display it looked like the contact point but actually it
wasn't. I would have thought it was too, until I was able to see the
previous frames in detail using the elecard software, which can
capture all video frames individually in sequence.
I apologize if it comes across abrasive or anything. I was just trying to
find out why there was just a discrepancy between the radar and formula.
Here's is the short explanation of how I know there is one more frame.
Looking at the sequence of frames:
- The toss moves the ball from right of the picture to left, as is consistent with pros' tosses. Moving in a parabolic motion from right to left.
- In this case the ball has clearly moved to the right from one frame to the next, so the ball must have been struck to cause it to move back toward
the right.
---- warning: long detailed analysis below ----------------
Frame:
(p1 - p4):
We see that the ball is traveling upward on the right side of the little
tree. It appears to go up in a more or less straight path.
(p4):
Here we see taht the ball exited on the ride side ofthe little tree.
(-2):
The has not droppe back into view of the camera yet. It will come in at
about the peak of the little tree.
(-1):
If you look carefully, you will see that the ball has just begun to enter
the frame where I have drawn a red arrow.
(0):
The has continued to drop into frame and the racquet has either made
contact or is about to make contactd. Just like the ascent, it is traveling
in a more or less straight path down. It is, however, slight to the
left of where it exited the frame on its way up. This tells me the toss
traveled it a parabola going right to left.
(1):
The ball has already been struck. How do I know? Because it is now A
LITTLE TO THE RIGHT of it's previous location in frame (0). This cannot
be due to the toss because the toss has a slight RIGHT to LEFT
path. Therefore, the ball must have been struck. The serve is going
toward the ad court so this makes sense. Why does the racquet appear
to be in front of the ball? Because the camera is slightly to the right
of the center line and drakulie has begun his pronation going left to
right. Just by coincidence of the location of the serve and camera, for a
brief moment the racquet is still in front of the ball. This is probably why
you thought that was the contact point.
Also, the racquet angle with respect to the court of the frame in which I strike
the ball is very similar to the frame 0 in the picture above. If your serve has
a lot of topspin then it is unlikely that the angle would facing so much more
down toward the ground than my serve, which has topspin but is not my
heavy kick serve.