Trackman vs foresight gc2 with hmt

[ZMax]

Good find bubba22.

It appears the gc2's flash is not used for the hmt. The rings of ir LEDs are used to illuminate the stickers. Frame captures start on club takeaway and ends once the dots return to the ball location or after the flash fires? Reflections from other light source and ball blocking some of the dots could cause problems.

[bubba22]

Yep. Stumbled on it today. Just as you say. I really wonder if placement of the dots is critical?
GM2 does waggling affect the unit?

[ZMax]

Foresight says its not critical because the dots from each frame are compared to with dots in other frames. They do state that dots can be placed on the hosel to help with face angle at ball location.

[ZMax]

As for the flash not being used by the hmt, its not needed. The ir LEDs are enough. But outdoor on a sunny day might be different. Anyway, the hmt cams are not taking photos of the club. In all the captures, the images are probably nearly all darkness with 4-5 white dots. I didn't see any mention of the speed or amount of frames captured during a particular club speed.

The faster the cams capture the frames, the more accurate the club speed and face angle.

[bubba22]

I agree.

[bubba22]

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

It wouldn't surprise me if Foresight will develop their own club add on gyroscope rather than integrating with another company. After all they are cheap to manufacture. I would hate to see what they would charge for that though!!!

[CPA]

Personally I think GC2 with HMT and intergtated with Swingbyte with video (2 cams) and targetline fix would be amazing, even drop off the HRT if cost an issue.

[Frans@france]

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?

- As you can not place each marker on each club on the same position the machine will identify the club based on the set of marker positions stored in the system. That's what I read. So the system would be able to see the difference between your 6i and 5i because the markers are not placed exactly the same.

- ridiculous that this patent has been approved. There is enough prior-art to be found about using markers on the club to measure club data

- Did someone notice that this technique will not work on clubs with roll and bulge! The markers always form a "flat" 3d geometric shape thus the system will not see the real face shape and orientation.

- misplacement of markers around the cog or sweetspot will make impact position data "incorrect". Most golfers don't have the tools to determine the cog and place the markers correctly. So a 0mm reading in reality is a 0mm displacement in relation to the marker position and not the sweetspot position. Same for the Lie measurements. Those markers need to be placed with extrem care.

- impact is not measured. The movement of the markers is forward estimated using an polynomial line fitting and then using a fixed ball size and pre-impact position the first impact point is estimated within that fitted line and that is then used to determine the impact data. Big questions here is which system is doing the ball position. I do hope that the CG2 system is also seeing some of those markers so HMT and CG2 data can be combined correctly.

- No calibrations between the two systems.

Good find!

[GolfMonster2]

Personally I think GC2 with HMT and intergtated with Swingbyte with video (2 cams) and targetline fix would be amazing, even drop off the HRT if cost an issue.

Cost is an issue, but there is absolutely no way I'm giving up my testosterone

[syhlif32]

Wouldn't the heel marker be obscured by the ball at impact? which would make face angle impossible to measure. Guess with a before and after impact face angle you could get a fairly accurate face angle by assuming a fixed rotational speed.
Hope the have a (14) very good template(s) to assist putting those markers on?

What stands out to me in the data are the large differences in spin axis on all but two of the shots!

Would have thought that Spin and Spin axis would be a strong point of the GC2?
Any logical explanation why they differ so much on the Spin Axis?

[ZMax]

- Big questions here is which system is doing the ball position. I do hope that the CG2 system is also seeing some of those markers so HMT and CG2 data can be combined correctly.
- No calibrations between the two systems.

Good find!

Ball positioning is done by the GC2 system. Under video, you can see the ir lights come on and follow the ball as you move it around in the hitting zone. The hMT cams are just another pair of eyes designed to look for dot patterns. From my understanding of the patent, they recognize the ball but ignore bright objects.

Correction: According to the flow chart, the images of the ball in the HMT captures are used to calculate the 3D ball location and thus the point of impact. I don't know whether this location is combine with the GC2's normal ball positioning.

I've always said the HMT is not $6500 accurate. It fills a need and does a decent job from the videos I've seen and gm2's limited data.

As for the spin axis, the data jives with what I've seen in my outdoor/indoor gc2 testing. Foresight's stated tolerance for side spin is a joke. For normal center contacted shots the gc2 is about 80-85 percent reliable. I wrote about this in the gc2 thread. Prior to the latest firmware, it was even worst. Shots that were not hit well can have exaggerated side spin numbers.

The gc2 is very accurate with ball speed and la. Ball path is also very good but accuracy tails off as the la increases, mainly with wedges. I'm just talking about 2 degrees off.

[bubba22]

With the HMT I don't like the fact that the ball direction on many occasions doesn't fit within the ball light rules. Barring a shank, the initial ball horizontal dirction should fall somewhere between the club face angle and club path.

[ZMax]

Bubba22, too bad we don't have the HMT data for the rest of the shots.

Shot 2 was a centered hit according to the HMT but ball launch direction doesn't add up.

[GolfMonster2]

I went to the range today to demo the Cleveland 588 MT & TT irons. I also wanted to recheck how the GC2 compared with observed ball flight. I could not get the GC2 to show a fade. Admittedly, I am fighting too much right to left at the moment, but I hit several of what were definite left to right shots into a right to left wind and the GC2 recorded left spin! I recall a fellow on another thread here was protesting about the same issue. I then went and had a look at the above data (afterward my suspicions were raised) and noticed that compared to Trackman, the GC2 on the whole measures more left spin.


Has anybody else noticed this? It could possibly be due to the unit not being levelled properly so that backspin is interpreted as side spin?

[ZMax]

Was this on mat or grass? Not level by 1-3 deg would effect LA and the calculated carry I would think. They can't expect people to take it outside and have it perfectly level. Last I checked, the GC2 doesn't come with a level.

Was the footing fully extended?

[GolfMonster2]

It was the range's device. Cased in the metal housing. In retrospect, the GC2 was on the ground and I hit of one of those heavy duty rubber based mats with artificial turf on top. So the GC2 was below ball height.

I will take my own GC2 to the range tomorrow to do a retest with case off and at the appropriate height. Will also be interesting to see how the 2 units compare when side by side (if this is possible for the same shot).

[ZMax]

Try again with GC2 at ball height or a little above. Make sure GC2 is flush with the metal housing. I don't know if 2 GC2 side by side would work reliably. The flash/strobes might not be synced causing too many images of the ball or overlapping images. It's worth a try.

[GolfMonster2]

If the GC2 being below the surface had anything to do with it, being below the surface would certainly fit with the GC2 interpreting back spin as left spin............

[CPA]

Number 1 instruction from FS. GC2 at ball height or just above....never below. They may need to update software as ZMAX found.

[GolfMonster2]

Went back to range and corrected the set up. Unit still giving excessive left spin. To get right spin need to hit a massive slice. I'm sure my unit is doing the same thing.

[bubba22]

GM2 contact Foresight ASAP while still under warranty!

[CPA]

Was that your unit GM or the range. Check their software no.

[GolfMonster2]

Sorry guys, it is def the range unit malfunctioning. My unit seems fine..

[bubba22]

My bad! Then the range folks have a problem!

[CPA]

Tell them to update their software and invoice them for the advice, or at least a cheap Cleveland.

[GolfMonster2]

Interesting, used the HMT at the range again. Was a bright sunny day. Head data was captured using the black faced hybrid, but not with the silver faced 588. The dots are silver so appears they need contrast to be picked up by the cameras.
Inside has never been a problem.

[CPA]

Do FS provide detailed instructions re HMT, dots and white or silver clubs?

Sunny day at this time of year in Auckland.....more unbelievable.

[GolfMonster2]

Does come with instructions, but totally inadequate for a product of this dollar value

[ZMax]

Sorry guys, it is def the range unit malfunctioning. My unit seems fine..

You were able to get both GC2s working side by side with no issues?

[GolfMonster2]

didn't get to sorry