Camera calibration Initial parameters

[3DWinter]

Hello Alexey and Metashape support,
I searched the Metshape manual and the forum, but I cannot find where/how Metashape comes up with the camera initial parameters.
For example, with the DJI Phantom 4 RTK, the focal length in pixels in the XMP file is 3666, but Metashape used 2840!
Looking at both the XMP and EXIF files, I have not found other camera calibration parameters. So where do these parameters come from? I don't think they are from a previous processing project or are they? Does Metshape download from an online library of camera parameters?

Thanks for this clarification!

[Alexey Pasumansky]

Hello 3DWinter,

If you haven't enabled loading calibration data from XMP, then Metashape would use available EXIF tags:

pixel_width = 1 / EXIF.FocalPlaneXResolution
pixel_height = 1 / EXIF.FocalPlaneYResolution
focal_length = EXIF.FocalLength