Optishot strange swing speeds

[knarf_st]

Received my Optishot two days ago and I am still testing. Got some strange results using the practice range with the swing speeds. If I use the same physical club (6 iron) and only change the club selection in Optishot I get different swing club speed measurements (when swinging the 6 iron at the same speed). For example club selection set to:
9i -> swing speed 70mph
6i -> swing speed 80mph
3i -> swing speed 85mph
driver -> swing speed 100mph or more

Does anyone have the same experience? Is my Optishot defect?

[FaultyClubs]

It's probably fine, mine is similar. The Optishot considers the club and the ball type when calculating swing speed since it can't measure it directly. My 6i speed turned out to be pretty close when I checked against a Doppler Radar. Are your 6i distances consistent with an 80mph swing speed in real life?

[bubba22]

Not sure that is correct. The swing speed should be based on the club length and the distance between the 2 sensor rows. The ball speed is simply the swing speed X a factor (smash factor) of around 1.4 or so to calculate the ball speed. The swing speed should be meaasured directly so seeing the differences when using a 6 iron, set to different clubs makes no sense. It should record roughly the same average speed each time, give or take a bit.

[FaultyClubs]

The point is that the swing speed ISN'T measured directly with the Optishot. With only two sensor rows and a ball inbetween, it can't be. It has to be calculated.

In any case, my Optishot behaves the way the OP described so it is probably working normally.

[bubba22]

I hear your point Faultyclubs. I always thought that the dd directly measured the swing speed between the 2 rows. Not at impact but at least directly between the 2 rows which should change with different clubs no?

[ZMax]

faultyclub is correct bubba22. that is why different ball type setting changes the speed/distance.

[bubba22]

That's really interesting. Never thought of it that way. Good point.

[FaultyClubs]

faultyclub is correct bubba22. that is why different ball type setting changes the speed/distance.

Yes and different clubs slow down differently due to ball impact. So that is why they are also part of the calculation.

One could add a second row BEFORE impact so that the swing speed could be measured directly the way bubba2 was thinking...but that adds cost...a smart algorithm is cheaper than a second row. Presumably DD did their system design well enough to conclude their calculated accuracy is good enough to save the cost of the second row.

[bubba22]

True and that is what P3pro does with the impact point.

[ZMax]

can't do to much more with the math. some people sweep while some hit down. add a LA camera to measure ball speed like GGS or Protee and problem solved.

[knarf_st]

Thanks. Thought that DD measured the swing speed as the time needed for the club to travel between the two rows. If this is not the case then it explains the differences in swing speed (with the same club). The distance is a bit less than in real life, but because the DD is higher than the floor I am standing on, I have to grip down a little bit so the swing speed and distance could be correct.