Antiletency tracking is annacu | Forum

Antiletency tracking is annacurate

Hello community, we recently bought antilatency ceiling tracking. Our results are not what we hoped they would be.

Here is a short demo of the tracking after finishing calibration thru Aximmetry camera calibrator on ver. 2022.3.0

The result from the calibration using Usra Mini Pro 4.6K G2 with Canon CN-18-80 lens seem to be accurate

https://www.canon-europe.com/for_home/product_finder/digital_cinema/cine_lenses/cn-e18-80mm_t4.4_l_is_kas_s/

Here is our Antilatency layout and parameters of our ceiling. Tiles were cut with the help of their drawing so they are accurate.

And this is the alt sensor mounted on camera right above camera sensor with the appropriate offsets.

Camera sits right below the ceiling and sees all the sensors as seen in debug app.

Is there something we are doing wrong or forgetting so that we can improve our tracking?

Thanks for any help.

Hurricane_Studio

CharlieBG

Hi colleague
Not have experience Antilatency but:
On video you need to make more precision tracking dally - now is shifting
And on the picture : Delta Head Positions (adjustment the tracker from sensor) - you have a lot numbers, not to be like that.
I did before and add manually positions from the floor to the sensor camera and offset to the tracker.
You got only Y offset by 9 cm to the center of camera sensor.
Check again the Basic Camera Calibrations - each step pan camera left and right and check via virtual Pole , need to be match at maximum not to drift .
One more hint - measure the real dastans from the camera sensor to the chare leg. measure and height on real leg. After on virtual Pole make the same distance(like the real one) on Z. Make the virtual Pole height like leg on chare. So now you need to find on your lens when pan left right up down to match on virtual one.
Best Regards

Hurricane_Studio

Hi Charlie, thanks for your advice.

I was busy these past days and I finaly got to do those changes as you've recommended.

The offsets:

But unfortunately I don't know if it's correct or what to do next, because it doesn't match.

Any other ideas?

Best regards,

Jimmy.

CharlieBG

Hi Jimmy.
I see some problems you not set up correctly like a - you use zoom lens - like on set to 18 mm zoom you need have a FOV more of 70 degree (Angle of View) regarding this page https://www.scantips.com/lights/fieldofview.html#top ...

virtualstarstudios.se

use the same like you - may be will help to set up the system.

Eifert@Aximmetry

Hi Jimmy,

The Aximmetry camera calibrator should be enough to make a better calibration than the one in the youtube video.
Note that you don't have a zoom encoder, so you can only do fixed FoV calibrations. Hence, when using the Aximmetry camera calibrator you can not change the zoom and the calibration is only good for that zoom level.

Warmest regards,

Hurricane_Studio

Hello, so I recalibrated the lens and tracking (without changing the zoom which i didnt do before so that shouldnt matter). Now I set my lents to 18 (previously 29) and it calculated almost perfectly.

But while calibrating there is noticable distortion on the lens. Is that of any concern while calibrating?

So after the calibration was completed I tried testing it with real measurments and placement but it didnt match and there was still noticable shift.

Thanks for your help guys.

Eifert@Aximmetry

Hi Jimmy,

It is not a problem if you see distortion on your camera's image while calibrating.

Did you set the correct Sensor width:

And you should be always directly under the Antilatency ceiling while doing the calibration.

If yes, then you could test if antilatency working correctly. You could start the old Basic Camera Calibrator and move your camera with the tracker on it and see if they are correctly changing in the calibrator's display:

P stands for position and R stands for Rotation.
Like you could measure 2 meter distance in one direction in your studio and move your camera along it and see if the position also changes by 2 meters.

Warmest regards,

REDEFINITION

Hi ! We can help you, we have plenty of experience troubleshooting antilatency , you can contact us here erick.briseno@redefinition.mx .

Hurricane_Studio

Hi Eifert@Aximmetry

Thank you for your advice.I have selected the correct camera so value for the sensor is correct and I'm doing the calibration under the ceiling so that's not the problem either. I tried moving it as you suggested and the values are not 100% accurate.

Here is a small diagram I made where you can see it

Eifert@Aximmetry

Hi Jimmy,

I think a 1 cm difference, like in your measurement, is well within the antilatency or human error rate. So probably something is wrongly set in Aximmetry.

Can you show how currently the shift inaccuracy in Aximmetry looks like? And how did you set the Input panel's parameters?
It could be you have now a different issue. Maybe it is just a delay and you need to set a tracking delay.

Warmest regards,

Hurricane_Studio

Here is the video https://youtu.be/aRZos85HuCs

And input parameters if you are talkeng about these.

The marker should be 2.7m from camera and the height of the yellow mark on the pole is 0,54m

Best Regards

Eifert@Aximmetry

Hi Jimmy,

The tracking delay seems to be incorrect, you likely will need a positive value, more on it here: https://aximmetry.com/learn/tutorials/for-studio-operators/setting-up-virtual-sets-with-tracked-cameras/#inputs

However, there seems to be a slight inaccuracy even without the delay. Could you do another calibration and see if the values here drastically change:

Including the Tracking results page.

Warmest regards,

Antiletency tracking is annacurate

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