Unreal 4.27 Lens calibration for Aximmetry

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Hi, I've been messing around with the new tools that came with 4.27, and I was wondering if there is a way to use the lens file we create inside Unreal In our Aximmetry projects. I've attempted to copy the results from the file that I made following a tutorial (https://www.youtube.com/watch?v=H5t2BwUGqkI&ab_channel=GregCorson), and paste It into a Camera Calibration file, but I didn't reach the result I wanted (also, I couldn't copy both Focal Lenght and Horizontal FOV due to them being linked to each other and I have no Idea why) :

I've did the tutorial using a URSA Mini Pro 4.6K G2, with a Rokinon 14mm f/2.8 lens by the way.

   tiagosilvadiretor

 
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Eifert@Aximmetry
10/7/2021 9:45:39 AM
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Hi,

The relation between Focal length and Horizontal Field Of View depends on your sensor size.
Base on your Unreal calibration, you probably did not change the default Sensor Dimensions values in your Lens File in Unreal:

Blackmagic URSA Mini Pro 4.6K G2 has a 25.34mm x 14.25mm effective sensor size (Super35), so you should probably have the same size there.

Once in Aximmetry Calibrator, you should change the Sensor width at Properties to your camera's sensor width:

And then, it should give you the same values as Unreal does for Focal Length and Horizontal FOV.

Warmest regards,

 
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Eifert@Aximmetry
10/7/2021 11:56:17 AM
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Hi,

Other than Horizontal FOV being different in what way did you experience a different result in Aximmetry?

We are working on closer integration between Unreal and Aximmetry, so any reported difference between them can help us better the user experience.

Warmest regards,

 
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tiagosilvadiretor
10/7/2021 1:44:57 PM
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Hi Eifert.

Yes, I actually had the sensor dimention set in both inside Unreal and inside Aximmetry (same values that you commented!). As for anything that was different from Unreal, was that I didn't use the Nodal Offset values inside Aximmetry, everything else I've managed to copy.

One thing I forgot to check, was to move the camera inside Unreal to see if something gets misaligned, since I only tested with a tracker moving in front of the camera, the result may be different when I actually start moving the camera Itself.

Thank you for checking out on this, when I have more time (perhaps tomorrow) I'll try to meddle with Unreal and see what I can get from her.

 
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tiagosilvadiretor
10/13/2021 9:06:17 PM
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Just did another calibration from scratch, while following every step with a clear mind. I think I messed up in adding the correct value of the focal length, causing the calibration to go wrong. After checking everything up again and re-calibrating the lens, everything now is working better than expected!

Thanks for the help Eifert.