Trackman vs foresight gc2 with hmt

[Frans@france]

[Frans@france]

white is CG2, green TM.

NO DATA means there was no data recorded by the CG2 for those parameters. I did not include the data that the CG2 did measure and the TM can't measure like LIE, impact point etc...

removed the one shot that the CG2 measured but was not present in the TM data.

[GolfMonster2]

Great thanks Frans. No doubt this will generate a lot of discussion. Bear in mind the GC2 wasn't aligned properly until later in the test. I will chip in to the discussion later in the day when I get a chance

[CPA]

BTW GM you can create PDF file from clubfitting by press of export button.

[ZMax]

Looking at the data above, I see a 5-8mph difference in club speed. Ball speed is pretty close. Backspin seems close. Big difference in spin axis on a few shots. TM has smash factor of 1.52 and 1.53 for a 4H?

And what happened to the HMT data for shots 4-9?

[bubba22]

Well I agree there certainly are differences. I wouldn't have expected tem to be exactly the same. Do you have the data with the unit aligned properly?

[ZMax]

Wasn't properly aligned or wasn't perfectly aligned?

GM2, when you placed the GC2 down, you must have at least eyeballed the alignment of the GC2 to the TM, right? Being not perfectly aligned would show up more in the ball launch directions. And also in club path and club face if you aligned yourself with the TM while the GC2/HMT was cockeyed. The ball launch directions shows that the GC2's alignment wasn't that far off from the TM. i.e. shot 1, GC had ball started more right than TM while in shot 2, TM showed ball started more right than GC2.

[GolfMonster2]

I just eyeballed the alignment and then adjusted based on where the ball actually went. so i would say not perfectly aligned.

[GolfMonster2]

I'll reviewthe data. I think the missing data was an exporting issue.

[ZMax]

GM2, I don't have the HMT and haven't seen up close in person. Does it have a flash of its own or does it use the flash from the GC2? You will be able see the flash fire if you look through a video camera.

[GolfMonster2]

It uses the flash of the GC2. Missing data is strange. I noticed some of the clubhead data was not showing on the iPad - something I never experienced indoors on the PC. I wonder if it was due to the bright daylight we had yesterday. Alternatively it may have been due to degradation of the clubhead dots because one or two of them did appear warn.

[Frans@france]

... TM has smash factor of 1.52 and 1.53 for a 4H?...

clubhead speed reported by the TM is the center speed. Ball could be hit on the toe with these shots. The toe is faster then the centre so as a result the ballspeed is also higher then when hit by the centre. The calculation ballspeed/clubheadspeed (=smashfactor) would therefore give a too high a value.

- Lateral face impact postion from the cg2
shot 1 : 13mm (towards the heel)
shot 2 : 0mm
shot 3 : 6mm (towards the heel)
shot 4 : NO DATA
shot 5 : NO DATA
shot 6 : NO DATA
shot 7 : NO DATA
shot 9 : -12mm (towards the toe)

[GolfMonster2]

clubhead speed reported by the TM is the center speed. Ball could be hit on the toe with these shots. The toe is faster then the centre so as a result the ballspeed is also higher then when hit by the centre. The calculation ballspeed/clubheadspeed (=smashfactor) would therefore give a too high a value.

- Lateral face impact postion from the cg2
shot 1 : 13mm (towards the heel)
shot 2 : 0mm
shot 3 : 6mm (towards the heel)
shot 4 : NO DATA
shot 5 : NO DATA
shot 6 : NO DATA
shot 7 : NO DATA
shot 9 : -12mm (towards the toe)

So which one is accurate/correct for "smash factor" in double inverted commas: GC2 or trackman? Trackman overeading or club illegal?

[GolfMonster2]

I have had a good look over the data. I don't really know enough about the ball flight laws to say if one monitor is giving clubhead data that is inconsistent with ball flight? Can we say if one monitor is correct and the other isn't without ultra high speed shutter analysis?

[Frans@france]

I have had a good look over the data. I don't really know enough about the ball flight laws to say if one monitor is giving clubhead data that is inconsistent with ball flight?

The CG2 data reports ball launch directions outside the triangle between face and path for all shots in this report. The one shot that I removed because there was no TM for it did include a launch direction within the face/path triangle

shot id 2 : 7.5 path 3,3 face 4.9 launch direction

[bubba22]

The CG2 data reports ball launch directions outside the triangle between face and path for all shots in this report. The one shot that I removed because there was no TM for it did include a launch direction within the face/path triangle

shot id 2 : 7.5 path 3,3 face 4.9 launch direction

Which is not possible according to the new ball flight rules. Would offset hits account for that?

[Frans@france]

Which is not possible according to the new ball flight rules. Would offset hits account for that?

even the old laws don't allow it

off-centre hit on a head having bulge and then reporting the centre face orientation and not impact face orientation could generate those weird values. However I assume the wedge used had no bulge

Reasons could be :
- miss-alignment between HMT and CG2 units
- definitions differences of path and face between the foresight and TM
- miss readings or calculations
- timing errors : pre-impact club data that is captured too early, both path and face are changing fast during that timeframe before impact. Ball data is always after impact data.

[bubba22]

I agree. I pointed this out when Cory posted his videos of the HMT on his YouTube page Par2Pro? There as well the ball horizontal launch direction fell outside the club and path. Take a look at Cody's videos on HMT testing.
http://m.youtube.com/user/Par2ProVir...ProVirtualGolf
It may be how Foresight define their club face/path readings. At that time someone from Foresight was supposed to contact me and discuss/explain this but it never happened. Perhaps this is a good time for one of us here to contact Foresight and get an explanation?

[Frans@france]

Perhaps this is a good time for one of us here to contact Foresight and get an explanation?

Yes, maybe a CG2 owner could do this....

[ZMax]

clubhead speed reported by the TM is the center speed. Ball could be hit on the toe with these shots. The toe is faster then the centre so as a result the ballspeed is also higher then when hit by the centre. The calculation ballspeed/clubheadspeed (=smashfactor) would therefore give a too high a value.

- Lateral face impact postion from the cg2
shot 1 : 13mm (towards the heel)
shot 2 : 0mm
shot 3 : 6mm (towards the heel)
shot 4 : NO DATA
shot 5 : NO DATA
shot 6 : NO DATA
shot 7 : NO DATA
shot 9 : -12mm (towards the toe)

I agree that toe hits will cause higher ball speeds to where the smash factor goes above 1.5 for a driver but can this happen with a legal 4H? As for the data in question, the HMT data for shots 2 and 3 don't support it since the impact were center for shot 2 and heel for shot 3.

[Frans@france]

I agree that toe hits will cause higher ball speeds to where the smash factor goes above 1.5 for a driver but can this happen with a legal 4H?

It happens for all clubs, every clubs turns closed so heel is always slower then toe, center speed is in between those two.

As for the data in question, the HMT data for shots 2 and 3 don't support it since the impact were center for shot 2 and heel for shot 3.

in order to understand if the reported impact position data are correct, these kind of tests need to include some kind of impact recording on the head like using a dry eraser marker.

[ZMax]

It uses the flash of the GC2.

I am now very curious about what actually triggers the HMT's cameras. To constantly capture in real time on the fly requires super high speed, light to be constantly on, and a lot of computing power. The HMT has got to be using a trigger. This can be verified using a video camera.

The GC2's flash fires after impact and that is a known fact. Question is, does the HMT fire the GC2's flash before impact for the HMT cam? If so, what triggers it? Or is the flash still fires after impact? Which means all HMT data are measured after impact.

If the HMT does trigger the flash before impact somehow, the flash would need to fire again after impact to capture the ball. Again a video camera can verify all this.

[ZMax]

in order to understand if the reported impact position data are correct, these kind of tests need to include some kind of impact recording on the head like using a dry eraser marker.

That is what I'm getting at....see my previous post above.

[Frans@france]

I am now very curious about what actually triggers the HMT's cameras. To constantly capture in real time on the fly requires super high speed, light to be constantly on, and a lot of computing power. The HMT has got to be using a trigger. This can be verified using a video camera.

The GC2's flash fires after impact and that is a known fact. Question is, does the HMT fire the GC2's flash before impact for the HMT cam? If so, what triggers it? Or is the flash still fires after impact? Which means all HMT data are measured after impact.

If the HMT does trigger the flash before impact somehow, the flash would need to fire again after impact to capture the ball. Again a video camera can verify all this.

could be a ring-buffer that stops recording as soon as the impact generates a trigger. then reading backwards into the ring buffer will provide pre-impact data. However lights\flash needs to be on all the time.

[ZMax]

Yup, that is possible. Flash stays on and a lot of captured frames to analyze

I do see what could be a ring of ir leds on both hmt cams. GM2, please post a video of the hmt in action when you have time.

[GolfMonster2]

OK will do

[bubba22]

Guys this may help http://www.google.com/patents/US20130190098

[CPA]

So my reading says the HMT is looking for the markers same as GC2 is looking for ball and when they leave field of view the swing capture process is started.

Interesting talk about intergration with Swingbyte/Skypro like device to capture full swing.

[bubba22]

Swing analysers integration is easy with any company. Though good for practice or teaching, it is not practical for game play. Yes CPA. The system locks in on the ball (main unit) and also the club (HMT). Once that happens then the capture begins and probably ends when the ball an club at gone. Golf what happens with waggles? it also looks like the placement of the markets is important to help determine the club type. I wonder how critical this is in its accuracy?

[CPA]

Good tip if using HMT not to waggle me thinks.