Verifying your current camera calibration
Note that the built-in camera calibration tables that come with the systems are only truly accurate if your cameras are setup in exactly the same way as when we made these tables.
As this is essentially impossible to replicate - i.e. your cameras will - in all likely hood - be setup at different distances from center line,
at different angles and at different distances from the hitting position, these built-in calibration tables will not produce ball speed and launch angle accuracy results
as well as if when they were custom made for your own particular setup.
To verify that your current camera calibration is accurate we need to simulate a 100 % consistent ball trace length in both the V and H cameras for all vertical and horizontal launch angles.
i.e. it is not humanely possible to exactly replicate shots by just physically striking balls at varying launch angles and paths within a 0.1 mph tolerance
For true 100% consistency we use a white paper tube of a known length on a pole that represents a ball trace at a constant speed
which can be placed at various vertical and horizontal angles during the tests.
i.e. as we know for sure that the length of the white tube will not vary during the tests, then if there is any discrepancy measuring ball speeds then it will be due to incorrect calibration.
The object of the calibration verification process is to check that the measured length of the ball trace (i.e. white tube) - which is directly proportional to the measured speed of the ball -
remains constant and consistent throughout all the path angles left and right and all varying launch angles from 0 to 60 degrees.
The V and Hcam calibration test involves using a black or dark long rod with a movable white plastic tube or paper roll attached to one end
and placed down at the other end in the tee holder on the hitting mat.
Place the end of the rod in the hitting mat's tee holder hole.
This represents the ball's initial position on the ground.
A tilt meter can be used to measure the real angle of the rod and the Hcam is used to measure the ball path.
With the aid of a helper holding the far end of the rod at varrying vertical angles and directions left or right
(or using some kind of support like a step ladder)
capture new V and H cam images of the rod by pressing the Enter key.
Pressing the Enter key on your PC's keyboard sends "Soft trigger" instructions to both the V and H cams.
Use blocks of some kind (e.g. step ladder, stools or chairs etc) to support the end of the rod to get the desired vertical angles.
Use the Hcam to check the desired ball path
Ensure that the "Ball Launch Position" has been set correctly in the Hcam window.
Start at Vertical angle of near 0 degrees and zero degree path (i.e. straight)
and set the scaling factor in the Vcam so that the distance measured in the Vcam
(i.e. the length of the white tube) is the same as the actual length of the white tube on the rod.
In the above example the known length of the white tube is 50cm and the measured length is 50.04 cm when the scaling factor is set to 0.2540.
This ensures that the speed of a ball leaving a trace this long is correctly measured.
In the above example the speed measured is 116.44 mph.
Now move the rod around - at random - at varying vertical angles and horizontal ball path angles and
- after pressing the Enter key on your keyboard to grab new images in both the V and H cams -
check to see what the measured ball speed is.
If all is well then the measured ball speed will stay reasonably consistent with every launch angle and path simulated by the rod and white tube
set at all varying vertical and horizontal angles throughout all tests.
If not - or is not within your acceptable tolerance - then you'll need to calibrate the cameras
Click the above button to read about camera calibration.
Don't forget !
Ensure no other Control Panel settings are also adjusting speeds and launch angles before doing the tests
If your Vcam is mounted on the left side of the enclosure, ensure that the "Vcam Left" option is ON
otherwise your calibration will be reversed
Also don't forget to set the distance your Vcam is from the enclosure center line
Currently distances are 5ft, 6ft and 7 ft.
If your Vcam is over 7 ft away from the center line then just use 7ft setting for now.
Other distances will be available later this year
Also don't forget to set the amount of calibration to 100% for both speed and LA to start with
Later you can reduce or increase the amount of clibration for both Speed and LA to suit
In the above example the speed calibration was reduced to 50% so that any ball speed adjustments for ball hit left or right will be 50% less
Note that the calibration tables where made with a ball to trigger distance of 5ft.
Later next month we'll have exact speed calibration percentages for various other ball to trigger distances
Also don't forget to set "Extended Calibration" ON and "Factory calibration" ON
Note that these are default ON with the new CP releases
And finally, don't forget to switch "Carry factors" OFF
and "Ball speed controls" to their default of 100%