change the lens value of a tracked project

Studio Operators Content Creation Content Sharing Camera Tracking Unreal

 

Hi everyone,

I can't change the lens value of a tracked project. i tried to change the mm in the blueprint of the ue4 project but the lens doesn't change.


can you help me, please?


thanks 

Adalberto

   adalbertolamp

 
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TwentyStudios
1/4/2022 12:40:40 PM
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What lens value do you want to change? Zoom should be the equivalent of mm, and you change that in Aximmetry, not in UE4.

 
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adalbertolamp
1/6/2022 5:41:34 PM
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Hi, thanks for your reply. 

I would like to change the mm of the virtual lens to the physical lens I use. how do I do that?

the only options i see are:

- Modify the scale of the TrackedCam module (I modify a value that does not have much to do with the mm of the lenses)

- Change the manual zoom inside the input module which modifies the calibration with the trackers.

thanks and Happy New Year


Adalberto

 
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Eifert@Aximmetry
1/19/2022 12:20:37 PM
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Hi,

The Focal Length of the lens can be directly converted into the Horizontal Field of View.

In virtual cameras, you can set the Horizontal Field of View (Zoom) when setting up the camera position/path: https://aximmetry.com/learn/tutorials/for-studio-operators/camera-mover-mouse-control/

In tracked cameras, you can add a Zoom Device to control the Field of View externally. Or use Manual Lens turned on with Manual Zoom:

If you turn on ON SCREEN Info, then you are able to see the Manual Zoom in FOV and Focal Length in the preview out put video of the camera:



There is a FOV Calculator module which you can add the flow to do some more direct calculation.
Like if you set the Param pin value to the Manual Zoom value and you set the Param Mode to Zoom Factor (0) with the correct Aspect. Then it should give you the Focal Length of the Manual Zoom value you use in the Inputs.

The Sensor Width will stay 36 in the internal calculation of the Camera.



Also, there is a Camera Calibrator program in the Broadcast edition of Aximmetry. Where you can set up more complex lens data and also converts Focal length into Horizontal Field of View:

Warmest regards,


 
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xaviprz
1/21/2022 3:50:12 PM
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Hello! How can i display the Fov in mm in the info? I only see FOV in degrees

 
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Eifert@Aximmetry
1/24/2022 1:00:34 PM
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Hi Xaviprz,

You only see FOV values cause you are using a virtual camera compound. In a virtual camera, what sensor width your virtual camera has is an arbitrary number. Hence the resulting Focal Length (mm) value will also be arbitrary.

You could edit the camera compound's info to show a Focal Length (mm) with FOV. But you are probably better off just by adding this info to the preview after the Camera Compound. This way you can easily update the camera compound with newer versions of Aximmetry:

Where the Fov Calculator module has Param Mode set to Zoom Factor (0) and Sensor width set to your preferred sensor width.
Also, in the above setup, the Format Scalars module's Format pin value is set to Focal: %.01fmm.

If you are certain that you want in the camera compound, I can show you that too.

Warmest regards,