GC Quad distances

[delaloi]

Took the GCQ to the range today for the first time. It seems to catch spin well; curvature reads are consistent, and it's good to see how much movement 100, 500, 1000 rpm of side spin means. Alignment works if you use the rod, but just sitting it down and eyeballing is not good enough. This is one of the reasons I went for the Quad over GC2 and glad I did, because even the Quad system is not perfect. I would think alignment would be a drawback with GC2, particularly indoors. I don't see how you can play sim golf unless you are sure the aim function is exactly right.

Anyway, reason for the post is I did some distance checks. Wedge distance so I could be sure where the ball is landing. At 75 yard range, GC Quad was consistently showing carry distances of 5-7 yards farther than actual ball flight. First I was thinking maybe that's because of using not-great range balls, but that should be captured in the ball data. I was hitting off a mat, not sure what effect that would have if any. I don't think wind was against. Temperature was cold, just a few degrees above freezing. Not far above sea level.

Any ideas?

[mthunt]

It's pretty funny about the draw biased comments all the time. My buddy was by yesterday and hit everything straight. I hit draws.

[Tommyseb]

i took my GC2 to the range, every single shot, approx 120 show the same shot shape on the GC2 app as i saw in the balls real flight, its entirely possible that Leo's single GC2 was faulty hence he sent it off to Foresight, i'd be very interested in him doing another comparison now he's got his unit back or with a unit known to be showing correct flight.

[LEO MODE]

GC2 draw bias is a common issue by users, not just me. It has been posted multiple times as I can see in this forum.

https://golfsimulatorforum.com/forum...ight-draw-bias
https://golfsimulatorforum.com/forum...ft-bias-issues
https://golfsimulatorforum.com/forum...ect-spin/page2

During my initial testing before sending it off to Foresight, I also tested it with my friend. Strangely, his occurence was less than I (me 7 out of 10, him 3 out of 10). Thus I also concluded that it is also very player dependent. If it doesn’t happen with you I am very happy for you because all other metrics should reflect everything close to real life. I should perhaps change my swing or something lol....

I did receive the recalibrated unit, and yes it did improve by about 5-7 degrees (they said the reason was because of harsh shipping/handling but it was sent in the protective hard carrying case...?? And that means every people who receive GC2 unit will always have to recalibrate because most of people get it by mail???) Anyways... it still had more left tilting result still differed by about 3-5 degrees (I would consider less than 3 degree tolerable but in some instances ball hooking was a bit extreme in some sense still). It definitely got better but the number of margin of error stayed the same. I also read Skytrak had similar occurence, so I’m guessing it is a common error that camera system gets just like how radar struggles with reading short shots indoor. The best thing is hit like 50 shots versus Trackman outdoor. I also contacted a robot testing facility to actually conduct one but since they said they use Trackman to measure the carry and the ball landing location so I decided not to use it since it won’t be a fair match for GC2 (they said they used to use humans to check the ball location but Trackman was confident after testing themselves that they no longer use humans anymore).

[Tommyseb]

what type of shots were you hitting? is it the horizontal launch angle that is being reported more left than you believe it to be? in my tests which were just after i'd finished my lesson i hit about 120 shots ranging from 54 degree gap wedges all the way down to the driver, i also hit some silly shots (on purpose) to see what the GC2 app showed on the ball flight and they were all identical shape to what i saw the ball doing. before i did that outdoor session i worked out the horizontal distance that was between each degree and created a image to display on my projector which had vertical lines with the correct spacing inbetween ranging from 10 degrees right to 15 degrees left with lines a each degree, and tried chips, medium and long irons and drives and nearly all displayed the HA angle as i'd expect based on the impact dent on my screen to within 1 degree or so, so at least with my unit i'm 100% confident its showing me the correct results...

[LEO MODE]

what type of shots were you hitting? is it the horizontal launch angle that is being reported more left than you believe it to be? in my tests which were just after i'd finished my lesson i hit about 120 shots ranging from 54 degree gap wedges all the way down to the driver, i also hit some silly shots (on purpose) to see what the GC2 app showed on the ball flight and they were all identical shape to what i saw the ball doing. before i did that outdoor session i worked out the horizontal distance that was between each degree and created a image to display on my projector which had vertical lines with the correct spacing inbetween ranging from 10 degrees right to 15 degrees left with lines a each degree, and tried chips, medium and long irons and drives and nearly all displayed the HA angle as i'd expect based on the impact dent on my screen to within 1 degree or so, so at least with my unit i'm 100% confident its showing me the correct results...

Just about any shots. I can be better than a robot since I’m a high handicapper and I don’t hit shots consisently every time which can show a variety of results.
HA (Launch Direction) and VA (Launch Angle) are not the one I’m talking about. Those 2 parameters had no issues with me and were very close to real life. It is Tilt Angle (Spin Axis) that is causing the difference. So as a result it causes the occasional hook.

See what I tested as an example out of many shots after I got it recalibrated. As I said earlier, after the recalibration it got better from 8 degrees on average difference to 3 degrees. But still when shots are not measured correctly, like with showing no Peak, Offline and Descent Angle as per attached, their margin of error window got bigger and often (it is kind of unpredictable too, so I assume it depends on the swing). In conclusion, if GC2 measures properly: great and accurate just like skytrak. If not: it will show you some whanky numbers (you see where I shanked the ball and went 40yds, but GC2 said I went 70yds) and ball flight which seems to happen more than Trackman, and believe me Trackman has some errors too but very rare I’ve seen.Trackman and HMT shows no data when not measured properly, and I think GC2 should adopt that too so we don’t have to believe the numbers.

This result is based on outdoor. Therefore indoor shouldn’t be any different. Hope this clarifies.

[Tommyseb]

those are some funky missreads, i will add that when i did my testing it was off a mat and in a shaded bay, i've read that sunlight can seriously mess up the readings of the camera based LM's like GC2 and Skytrak, there's a post around on here somewhere where the guys use makeshift umbrellas to put shade over the hitting area, were you hitting off the grass, as i also heard that can confuse camera LM's if there's bits of grass and turf flying around after impact. in my test out doors in a shaded range bay and overcast winter UK conditions i didn't get one miss read with 0's like on your tests.

[LEO MODE]

No GC2 was facing west and the Sun was facing north, behind the ball. It didn’t have any direct sunlight impact. And I was hitting off of a mat. Interestingly, I had no issues reading off of a turf lol, maybe because as I told you before I am a picker. I rarely take divots.

Now I wonder if GC Quad got better in terms of taking photos (since it’s not a flash now but an infrared AFAIK) as well as algorithm/calculation.

[Tommyseb]

do you not think there could still be a issue with your GC2, out of those 14 shots 7 were complete miss reads? i didn't get 1 miss read from around 120 shots... i would definately think the Quad is more accurate, but i truely believe the number of miss reads you got there is not indicative of of correctly functioning unit, and it would be remiss to think that all GC2's behave in that fashion?

[LEO MODE]

Tommy, I never said all GC2's are weird and faulty. It is a known issue that people experienced GC2 being draw biased and misreading here and there. It goes just like how you transitioned from Skytrak to GC2. The higher you pay for the launch monitor, the more hope you're trying to get for less margin of error. Trackman just had less margin of error. I think Skytrak could be a fantastic device if read properly, but why did you change it? I'm sure some people have no issues with it.

Just to be objective again, I would be careful to believe all of your 120 shots were accurate (unless you had a Trackman next to you or something), because GC2 outputs data regardless of error. The non-read shots that I had above were very close in all other data, just not showing Peak, Offline and Descent Angle so non-read is being different from mis-read and I don't think those were mis-reads.

The main purpose of me doing the test was simply because I loved GC2 but since it was giving me some weird ball flight at PGA Superstore, I decided to test them out both indoor and outdoor and realized that GC2 had more margin of errors.

Is GC2 a bad product? Absolutely not. I think it's a wonderful product at its price point. Then is GC2 an accurate product? It is but not always since it showed margin of errors. Then is Trackman an accurate product? Again, it is but not always since it still showed margin of error. I was hoping re-calibration directly from Foresight HQ would remedy the issue but unfortunately it didn't completely. This was my experience.

[Tommyseb]

Hi Leo, just to clarify, I was looking at the shot range view on the gc2 app, and comparing the plotted ball flight to what I visual saw with my eyes that the real ball did, obviously I couldn't see if the spin carry peak height were correct, but I was only inferring that the shot shape was 100% correct for every single shot of the 120 I took, now if it hadn't have calculated the offline value like in your misreads I'd expect the shot to go arrow straight, which none of mine did (unfortunately ) unless it still manages to show a curving ball flight left or right but still report zero offline. Next time I'll be sure to check the numbers as well as the ball flight.

I switched to a gc2 from ST because I got tired of the dodgy reads with short chips, before I sold my skytrak I ran the gc2 and ST side by side looking at the same shot, and whilst I got a ton of no reads from both units, assuming the camera flashes interfered with each other, the ball flight and reported numbers were pretty much identical for drives irons and wedges, only the short chips was the HA sometimes a bit wayward on the ST. I also found the ST was more forgiving when putting on dodgy mats as I believe it takes the photos over a smaller sized window. Had I not got the gc2 for such a good price I wouldn't have considered the switch to be honest.

out of interest when you hit your gc2 inside to you get the same number of misreads? I.e it's read the ball picked up some stats but reported 0 for peak height etc?

[LEO MODE]

Right when I had those shots with no Peak Offline and DA, it didn’t show me any ball flight on the app. I would love to see all 120 shots showing the same ball flight as in real life. To me ball flight is also very important along with other parameters. And I am glad that yours is correctly showing because that’s how I want mine to look like.

[mthunt]

I don’t get misreads either. I guess YMMV

[Baller]

I think the title of this thread needs to be changed to GC2 bias or issues or something...

[p3eps]

What are you defining as a mis-read?
I’ve had a GC2 for almost 3 1/2 years and hit countless shots. I could genuinely count on 2 hands the number of shots that I’ve had with ————— across the screen... and most of them have been me moving the ball with my hand when it’s placed!
I added the HMT about 9 months ago, and I occasionally get some missing HMT data.

[delaloi]

Leo, that data is pretty striking. It looks to me like that particular GC2 unit is not working properly. I don't understand why it would give you readings for ball speed and launch angle, but then zero for peak, offline yards, and descent angle. Those parameters are just calculated from the initial ball read -- just arithmetic based on measurements already taken. In other words they are not misreads or failures to read the ball.

Now, ball speed and spin measurements may be accurate or maybe not, that's a different question.

[LEO MODE]

Maybe I have a radiation that affects all GC2's? lol. I tested 2 other GC2s previously and I had this occurring on all devices. Lastly, this happened both indoor and outdoor. As I said, ball speed, spin, all other data that showed present were accurate. No complains in that.

Trackman also has non-reads/mis-reads too. GC2 is not a perfect device, as I know a handful of people getting non/misreads here and there.
Just to clarify this again, I would say this particular incident is a 'non-read' and not a 'mis-read' which can happen. What I did notice was that when non-read, or mis-read, it gave more margin of error than when read properly. That is my conclusion.

[delaloi]

Weird (your GC2 performance, not your interpretation of it).

[delaloi]

I had the GCQ at the range again on the weekend, and this time distances looked right by eye. Maybe there was some wind against on my first try as in the OP. At least nothing howling wrong this time. Within the margin of error of my swing. :-)

[LEO MODE]

Where r u located? I am willing to do some intensive side by side testing.

[LEO MODE]

delaloi did you find out if carry inflation was due to the altitude you are at? (Like 2000ft above?)

did you also get a chance to compare the driver carry distance with a Trackman? I wonder if it improved over GC2 as GC2 low spin driver has excessive carry at times.So