Why does Hugin stitch two pictures the wrong way with big steps?

Question

When trying to stitch a picture of a car out of two photos, I always get a wrong stitch with well-visible "steps", especially on the left rear lights:

I've tried fiddling around with the control points, but no use:

See the archive at Google Photos for the original pictures.

So, what is wrong here? Is it because I was too near?

Answer 1

Three issues are very apparent:

• You did not rotate the camera about the no parallax point, often mistakenly called the nodal point. This is readily apparent in the relative alignments of various features between the two images. The alignment report shows large errors between control points. Properly done, the error should be less than 5 pixels, not 36 to 120 pixels.
• You need at least 30% overlap to generate good control points. You were close, but I had a hard time trying to find enough features to manually select control points (just in case the auto control point generator was picking bad points).
• You used different focal lengths of 24.0mm and 28.0mm (this shows up visually and in the EXIF data. This is not a valid set of images to create a panorama.

When taking panorama shots, it is important to rotate the camera about the no parallax point. Serious folks use a special plate on a tripod to offset the camera so the no parallax point is on the axis of rotation.

Casual panoramas can be taken without a tripod and special gear by simply resting the lens on top of your finger and rotating the camera on your finger while holding your finger as still as possible. It's not perfect, but it will generally give you acceptable results since Hugin, and other stitchers, try to match seams.

You should also use manual exposure as aperture changes can affect depth of field and you want the exposures to match between images (Hugin will do auto exposure matching).

Running your images thru Hugin (version 2020.0.0.2) and letting the program create the control points, my output was similar to yours.

If you are interested in taking panoramas, there are many Web pages with tutorials on finding the no parallax point and the techniques in taking the images.

[Edit] Just remembered, Hugin can handle different focal lengths. In the photos tab: Geometric, select Positions and View (y,p,r,v). The pano of your image looks better, but still has seam issues.