GoPro on a head mount :)

Greg G

Professional
Realtime speed had so much bouncing it wasn't nice to watch. I dunno if the cap mount was moving a bit, or my head moves too much @_@

Plus it shows how good the high speed mode of the new model is!
 

Dimcorner

Professional
Peoples head just move a lot more than you perceive. Your brain is just very good at compensating for most activities.
 

BMcFarlan

New User
I've been so tempted to do this. A friend has a newer GoPro and I think it would be fun to "re-see" some good rallies from the first person perspective.

Did you find it to be beyond awkward, or would it be possible to wear for some aggressive rallies? I'd think it would be entertaining to record a couple of 20 shot exchanges to really demonstrate the POV of the player.
 

Greg G

Professional
I think a chest mount would be more stable. The head mount wasn't too uncomfortable, but I don't know if you could really play a competitive set with it on. Well you could, but you'd probably be too distracted by it :)

Well I feel better after watching Fed & Stefan's Google Glass video.

http://youtu.be/9Eabp3Jpy-I
 

Bdarb

Hall of Fame
chest mounts are better for this type of thing because it stays more still. I guess it depends on your strokes though. Backhands would look weird. Why again did you do this??
 

Chas Tennis

G.O.A.T.
Upgraded my GoPro HD to the newest GoPro 3+ Black Edition. Much clearer video! Tried using it mounted to a reversed cap (cap clip mount). Camera was clear, but the mounting location didn't turn out as nice as I thought it would :neutral:


groundstrokes

overheads

serves

Verdasco did better:
@Greg G - if your read this please update us on the GoPro head camera and tennis strokes. It looks perfect for showing players how they look at the ball. The Verdasco video that you posted is one of the few that I have seen of pro players.

I think that I am looking a large percentage of the time. The question now is, am I looking at impact from the best angle?

There is an issue of whether the pros are mostly looking through the back of the racket face or not. Simple video observations can settle this issue. We see some pros that appear to look through the racket strings to see impact, but we can only see that when the camera angles are favorable. A favorable angle would be camera, head, racket strings and impact somewhat in line. The benefit of looking through the back of the racket strings would be that you might have a better idea of where on the racket face the ball was impacted. What you see would have motion blur defects such as they are.

The GoPro head mounted camera shows directly what a player would be able to see at impact - if they also directed their eyes. Take a racket in your hand and see what you would see, particularly, as the impact position moves farther out front. A forehand technique with a Semi-Western or Western Grip may be easier to use for viewing the back of the ball. Compare the Verdasco forehand impact to the OP poster's impacts in the thread GoPro on a Head Mount.

Advice depends on the technique. For the forehand, the pros have significant rotation of the uppermost body, backward and forward, and use considerable separation. If your forehand technique does not have similar motions, what the pros are doing might not apply for other techniques. ?
 

Greg G

Professional
Hey Chas! Sorry I haven't used it since that one time. Maybe I should break out the GoPro and have another go :p
 

Chas Tennis

G.O.A.T.
We had a recent thread on watching the ball. It appears on ground strokes that many/most ATP players are looking through the back of the racket strings to see the ball at the time of impact. I believe that but have not studied it enough.

What the players on the forum are doing, percentages, is not clear. ?

Your head cam could show everyone exactly how they are directing their heads, especially at the time of impact, and what they are viewing at the time of impact and before. This looks like a great observation, feedback for the forum readers if they have a head cam available.

I believe that for the forehand I am not looking through the back of the strings but more down past the higher edge of the racket.

It seems to me that, like me, posters do not know how the ATP players or they themselves are looking at the ball.

Look at your forehands, 8 & 44 sec and one hand backhand 1:26. Your forehand ball watching is like I think mine is, more looking past the higher racket edge. Your one hand backhand at 1:26 shows you clearly looking through the back of the racket strings at impact.

The head cam does a great job of showing how your head is pointed during the tennis stroke.

If impact were moved more toward the net you would be able to look through the racket strings on the forehand. Grip change to semi-Western? You already must be doing it for the backhand based on the one BH in this short clip.

Do you have ball watching goals? Do you have a model player for ball watching?

I'd like to see Medvedev in a head mount with his head-flicking ball watching technique.

This would be a great instruction tool for an instructor. (@SystemicAnomaly )
 
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Chas Tennis

G.O.A.T.
See this entire thread for discussions and evidence on looking at the ball.

1) Federer - holds his head very stable before, during and after impact looking at the ball. Great result.
2) Djokovic - is not so consistent, is seen to not be looking always directly at the ball impact location. It is difficult to argue with his results. Great result.
3) Medvedev - has the head flicking technique where he very rapidly flicks his head to look toward the ball/impact(?). This seems to violate the 'don't move your head while striking the ball' advice. ?? It is not a rare technique. Great result.
4) Forum readers - ?

In earlier posts, clear high speed videos from elevated camera angles were shown. In particular, these show the racket face from behind, as an oval, and the ball approaching the oval, impacting it and leaving it. This provides compete information - to some unknown accuracy - to the player as to where on the racket face the ball was impacted. I do not know how this information is perceived in the brain. First guess, it is perceived by the brain somewhat as a video frame that has considerable motion blur. ? Can the eye and brain possibly make use of this imperfect impact observation or earlier observations to more accurately strike the ball? Pros prove to us that the answer is yes, because they are only using their sight.

Compare the ball watching of Greg G to that of Verdasco using the GoPro camera. I hope that Greg G can update us.

Arguing about what the eye plus brain might or might not 'see' (undefined) or perceive while presenting no other evidence is not very creditable.

High speed video observations have been presented that show the arrangement of the eye to racket head to impact that would allow the ball's location on an oval racket face to be observed. But the response of the eye & brain to motion blurred light is not known on the forum.

We could all do experiments and see if we can locate the ball impact on the racket face by looking through the back of strings of a racket head well out in front of us. "Out in front of us" means back along the ball's trajectory. The racket head has to be seen as an oval and not face at a glancing angle. Report back what you think you saw....
 
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Chas Tennis

G.O.A.T.
Here's a good video :)

That is a very informative video showing how that player, Karue Sell (Highest ATP Ranking #371, UTR 15.01) watches the ball. He does not direct his head at the ball, but looks well out into the court. When pressured deep, the ball appears to be struck farther back relative to where his head is pointed.

The video shows inconsistency on where the ball is struck relative to where he is looking. Even if his eyes are being redirected, because of the eye's and camera locations he must be seeing what we are seeing in the video to the side in the camera's field of view. Usually, the ball is seen through the back of the racket strings, especially on the backhand side. Many times on deeper heavy paced balls the head was not redirected to be able to get the racket in the camera's field of view.

I looked at many impacts, many others were not visible, but did not view all visible and do percentages. Karue Sell does not use the Federer stable head technique viewing directed at the ball, nor the Medvedev quick head flick technique, he points his head several feet back into the court. His head is stable. Dojokovic seems to vary his viewing location sometimes. ?

Look at the video and find some forehands and backhands with a good frame showing impact, notice the angle of the racket shaft, that angle usually indicates that he must be viewing impact through the back of the racket strings.

Based on the title of the video, I was heart broken that Naomi Osaka was not wearing the GoPro head mount.


If anyone knows Sell, show him this analysis and tell him that his ball viewing technique is very questionable.

@Greg G, the GoPro head mounted can tell your a lot about your viewing technique. Suggest that you read the thread on watching the ball and pick a technique.

One issue is that if the ball is struck more forward, impact is more likely to be viewed through the strings from behind. If your ground stroke techniques are not impacting far enough forward then... ???

+ @SystemicAnomaly
 
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SystemicAnomaly

Talk Tennis Guru
That is a very informative video showing how that player, Karue Sell (Highest ATP Ranking #371, UTR 15.01) watches the ball. He does not direct his head at the ball, but looks well out into the court. When pressured deep, the ball appears to be struck farther back relative to where his head is pointed.

The video shows inconsistency on where the ball is struck relative to where he is looking. Even if his eyes are being redirected, because of the eye's and camera locations he must be seeing what we are seeing in the video to the side in the camera's field of view. Usually, the ball is seen through the back of the racket strings, especially on the backhand side. Many times on deeper heavy paced balls the head was not redirected to be able to get the racket in the camera's field of view.

I looked at many impacts, many others were not visible, but did not view all visible and do percentages. Karue Sell does not use the Federer stable head technique viewing directed at the ball, nor the Medvedev quick head flick technique, he points his head several feet back into the court. His head is stable. Dojokovic seems to vary his viewing location sometimes. ?

Look at the video and find some forehands and backhands with a good frame showing impact, notice the angle of the racket shaft, that angle usually indicates that he must be viewing impact through the back of the racket strings.

Based on the title of the video, I was heart broken that Naomi Osaka was not wearing the GoPro head mount.


If anyone knows Sell, show him this analysis and tell him that his ball viewing technique is very questionable.

@Greg G, the GoPro head mounted can tell your a lot about your viewing technique. Suggest that you read the thread on watching the ball and pick a technique.

One issue is that if the ball is struck more forward, impact is more likely to be viewed through the strings from behind. If your ground stroke techniques are not impacting far enough forward then... ???

+ @SystemicAnomaly
Don't know anything about this subject (GoPro). Will have to take a closer look at the other thing you mentioned at another time.
 

Chas Tennis

G.O.A.T.
Don't know anything about this subject (GoPro). Will have to take a closer look at the other thing you mentioned at another time.
The GoPro is a way to record how your head was pointing and where your eyes were at impact and other times. You can forget the GoPro and take a racket in your hand and see the racket head for various positions of impacts, especially impacts forward or backward. This answers the question of looking through the back of the strings or not.
 

SystemicAnomaly

Talk Tennis Guru
The GoPro is a way to record how your head was pointing and where your eyes were at impact and other times. You can forget the GoPro and take a racket in your hand and see the racket head for various positions of impacts, especially impacts forward or backward. This answers the question of looking through the back of the strings or not.
Agree fully with the post above this one. The GoPro can tell you were your eyes are directed. But it doesn't tell you what your eyes / brain actually sees. I do not see strings and do not even see the ball at impact. What have you seen?

"Looking through the back of the strings" still sounds pretty meaningless to me. The racket head is moving thru the contact zone much too briefly to see much of anything. Can you even tell that you have strings in your racket when it flashes through your contact zone?
 
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Chas Tennis

G.O.A.T.
Agree fully with the post above this one. The GoPro can tell you were your eyes are directed. But it doesn't tell you what your eyes actually see.

"Looking through the back of the strings" still sounds pretty meaningless to me.
Look at the backhand impact frames in the Karue Sell video. I believe that nearly all are viewed through the racket strings, the racket head appears as an oval more or less. At impact he must have been looking through the back of the strings to see impact. Once the eyes, racket and ball are in specific locations and the racket head is between the eyes and the ball then ball impact must be seen through the strings.

Through most of my tennis life I believed that I should see the ball arriving from my left and the racket coming in from the right (I'm rightie). I believe that I often make that happen for forehands by impacting more to the side and less in front. See 6:44 impact frame below.

I don't think the forum players have a clear idea of how they look at the ball. I have not played in a year and a half and am not looking at my forehands. I'm not sure what I see.

Karue Sell Head Cam

Examples with ball impact observed.
2:55 Forehand_Racket seen as oval, ball impact seen through the strings.
4:35 2H Backhand_Racket seen as oval, ball impact seen through the strings.
6:44 Forehand_Racket seen edge on, half of ball in front of strings, half of ball seen through strings.
7:12 2H Backhand_ Racket seen edge on, ball seen in front of strings.

At impact, Karue Sell could have only seen the above things as his eyes were located close to the GoPro. It does not matter how his eyes were pointing.

If we saw the head cam on Naomi, what would we have seen?
 
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yossarian

Professional
Do you know when a swimmer turns their head to breathe during a freestyle stroke? Do you think if you put a green letter H in their visual field as they turn their head that they’d actually see a green letter H?

Do you think a baseball player at impact is actually seeing anything remotely related to the ball hitting the bat?

This is the worst case of paralysis by analysis that I’ve ever seen. But, if you’d really like to get answers to your questions, leave a comment on Karue Sell’s video or reach out to the channel directly and ask. Ask if he’s trying to look through his racquet to see the ball at impact

Report back with your results
 

SystemicAnomaly

Talk Tennis Guru
Look at the backhand impact frames in the Karue Sell video. I believe that nearly all are viewed through the racket strings, the racket head appears as an oval more or less. At impact he must have been looking through the back of the strings to see impact. Once the eyes, racket and ball are in specific locations and the racket head is between the eyes and the ball then ball impact must be seen through the strings.

Through most of my tennis life I believed that I should see the ball arriving from my left and the racket coming in from the right (I'm rightie). I believe that I often make that happen for forehands by impacting more to the side and less in front. See 6:44 impact frame below.

I don't think the forum players have a clear idea of how they look at the ball. I have not played in a year and a half and am not looking at my forehands. I'm not sure what I see.

Karue Sell Head Cam

Examples with ball impact observed.
2:55 Forehand_Racket seen as oval, ball impact seen through the strings.
4:35 2H Backhand_Racket seen as oval, ball impact seen through the strings.
6:44 Forehand_Racket seen edge on, half of ball in front of strings, half of ball seen through strings.
7:12 2H Backhand_ Racket seen edge on, ball seen in front of strings.

At impact, Karue Sell could have only seen the above things as his eyes were located close to the GoPro. It does not matter how his eyes were pointing.

If we saw the head cam on Naomi, what would we have seen?
You appear to be completely missing the point. There is no doubt in my mind that Federer fixes his gaze on his contact point. (I've been saying that very thing for ~15 years). Snapshots of Roger, at or near contact, "appear" to show that he is looking thru his stringbed at the ball. High speed video "appears" to show the very same thing.

The point is, the view given by the camera is a deception. You seem to be drawing false conclusions from these images and videos. Highly doubtful that Roger sees his strings at contact, much less thru his strings. Highly doubtful that he actually sees the ball at the contact point either.

Roger is NOT looking at the ball thru his strings even tho that is where his gaze is fixated.
 

yossarian

Professional
You appear to be completely missing the point. There is no doubt in my mind that Federer fixes his gaze on his contact point. (I've been saying that very thing for ~15 years). Snapshots of Roger, at or near contact, "appear" to show that he is looking thru his stringbed at the ball. High speed video "appears" to show the very same thing.

The point is, the view given by the camera is a deception. You seem to be drawing false conclusions from these images and videos. Highly doubtful that Roger sees his strings at contact, much less thru his strings. Highly doubtful that he actually sees the ball at the contact point either.

Roger is NOT looking at the ball thru his strings even tho that is where his gaze is fixated.
Chas has come to the conclusion that because he can see the ball through the strings at impact when watching video footage, the player must also be seeing the exact same thing. I don't want to be mean, but it goes hand-in-hand with his ability to conceptualize anything people write on these forums with a viewpoint that isn't identical to his own.

For all we know, the person in the video could be closing his eyes at contact. Unlikely, but you can't draw any definitive conclusions from the footage

Still, this is probably the stupidest thing I've ever seen someone become fixated on related to tennis technique.
 

Chas Tennis

G.O.A.T.
You appear to be completely missing the point. There is no doubt in my mind that Federer fixes his gaze on his contact point. (I've been saying that very thing for ~15 years). Snapshots of Roger, at or near contact, "appear" to show that he is looking thru his stringbed at the ball. High speed video "appears" to show the very same thing.

The point is, the view given by the camera is a deception. You seem to be drawing false conclusions from these images and videos. Highly doubtful that Roger sees his strings at contact, much less thru his strings. Highly doubtful that he actually sees the ball at the contact point either.

Roger is NOT looking at the ball thru his strings even tho that is where his gaze is fixated.
The eye senses the direction of light arriving at the eye. If something is moving rapidly that causes motion blur. For the tennis ball the eye obviously tells us pretty well where the ball is located, as we can hit it.

I have concluded that high level players probably are seeing a blurry image of the racket head, as an oval shape, with the ball as a blur somewhere inside that oval. And how the pros view the ball is not well known even though we know how some pros view the ball. Examples, Federer, Medvedev and Djokovic, top players and each has a different ball viewing technique. I also believe that many average players do not look at the ball as the pro players do.

Observations on this issue can be made with a GoPro camera in a head mount. As an example, I showed an ATP Challenger level player with a GoPro head mount. The camera recorded the impact inside the oval of the racket head, viewing through the strings. The impact was also observed with the racket edge toward the camera and not viewing through the strings. Both forehand and backhand examples were shown. These GoPro images are in much better focus than how the eye would see the ball for a tennis stroke. But the eye only has to locate the light from the ball for the tennis stroke. Seeing the ball in focus, or the strings in focus, is not necessary to locate the ball.

A simple way to look at this is to trace the light reflected from the ball to the eyes. It has to go through the racket strings to get to the eyes or it doesn't.
 
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yossarian

Professional
When things move, the eye senses the direction that light arrived at the eye. For the tennis ball the eye obviously tells us pretty well where the ball is located as we can hit it. I have concluded that high level players probably are see a blurry image of the racket head as an oval shape with the ball as a blur somewhere inside that oval. I also believe that the average player does not look at the ball as the pro players. And how they view the ball is very poorly known.

Observations on this issue can be made with a GoPro camera in a head mount. As an example, I showed an ATP Challenger level players with a GoPro head mount. The camera recorded the impact inside the oval of the racket head viewing through the strings and also observed the ball with the racket edge toward the camera. Both forehand and backhand examples were shown. These images are in much better focus than the eye would see the ball for a tennis stroke. But the eye only has to locate the light from the ball for the tennis stroke. Seeing the ball in focus, or the strings in focus, is not necessary to locate the ball.

I thought that you might be interested in the GoPro as a tool for evaluating the ball viewing habits of tennis students.
Still missing the point
 

Chas Tennis

G.O.A.T.
Nice find!

Is there some way to single frame on Instagram? Very difficult to catch ball at impact. Is there a slider bar as on Youtube?

I guess somebody could video the video playing on the screen and do single frame on that.

From the thumbnail shown at impact that frame appears to be a higher level player looking through the back of strings to see his forehand impact. When the racket shaft has that tilt, seen in the head cam, and is closer to the net than the player, he has to be looking through the strings when impact occurs. I catch others balls close to impact but unless Instagram has a way to do single frame it is very inferior to Youtube and Vimeo for tennis stroke details.

He seems to have a consistent head point direction to the forehand area where impact will occur. He seems to look toward the net shortly thereafter. ? @Greg G, How does your forehand head pointing compare?

If I were a tennis instructor I'd sure get one of those head cams and use it to evaluate my students. 240 fps would catch nearly all balls at impact or very close to impact.
 
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Greg G

Professional
I just try to look at impact point. Do i actually do it? Who knows, it just helps keep my head still :)
 
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