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[Alex Romosan <2064625@xxxxxxxxxxxxxxxxxx>]

I guess if the manufacturer is Apple then don't correct (at least if the
model is iPhone SE (3rd generation)). I'm trying to get data from non
Apple phones to understand how the 35mm focal length equivalent is
reported.

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https://bugs.launchpad.net/bugs/2064625

Title:
  35mm focal length on iPhone SE3 2nd generation over corrercted

Status in Hugin:
  Incomplete

Bug description:
  This is for an iPhone SE 3rd generation. Looking at the exif data for
  a zoomed picture I can see:

  Lens Specification  |3.990000, 3.990000, 1.8, 1.8
  Lens Make           |Apple
  Lens Model          |iPhone SE (3rd generation) back camera 3.99mm f/1.8
  Digital Zoom Ratio  |1.951
  Focal Length in 35mm|55

  For a normal picture:

  Focal Length in 35mm|28
  Scene Capture Type  |Standard
  Lens Specification  |3.990000, 3.990000, 1.8, 1.8
  Lens Make           |Apple
  Lens Model          |iPhone SE (3rd generation) back camera 3.99mm f/1.8

  Turns out the reported focal length for a zoomed picture is already
  corrected for the digital zoom factor so
  src/hugin_base/panodata/SrcPanoImage.cpp:542 over corrects by
  multiplying again with the digital zoom factor ending up with an hFOV
  too small. I just commented out line 542 and now when I add the zoomed
  picture I get an hFOV of 34.9 (which is what I would expect) instead
  of 18.3 (wrong).

  --- a/src/hugin_base/panodata/SrcPanoImage.cpp  Wed May 01 19:41:11 2024 +0200
  +++ b/src/hugin_base/panodata/SrcPanoImage.cpp  Thu May 02 15:18:02 2024 +0200
  @@ -539,7 +539,7 @@
       const float digitalZoom = Exiv2Helper::getExiv2ValueDouble(exifData, "Exif.Photo.DigitalZoomRatio");
       if (eFocalLength35 > 0 && digitalZoom > 1)
       {
  -        eFocalLength35 *= digitalZoom;
  +    //    eFocalLength35 *= digitalZoom;
       };
       float focalLength=0;
       //The various methods to detmine crop factor

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