I clicked a 2-shot Pano of the Boot Arch during the blue hour for Foreground. Then I clicked ten Milkyway shots for each of the two angles for the purpose of stacking. I used SunwayFoto DDP-64SI rotator, so the angles are perfect upon rotation.
I used Sequator to stack the two Milky Way shots, resulting into two noise free shots which I uploaded it back in to LR to create a Pano.
Once I built the Pano, then I tried to blend the foreground Pano and the Milky Way Pano shots together.
But when I try to do that, the two pano don't exactly align. I used PS > EDIT > Auto Align.
Equipment - Canon 7d Mkii + Rokinon F2.8 Lens + manual focus set to infinity.
Foreground shot: F2.8 / ISO 6400 / SS - 211 seconds
Milky Way - F2.8 / ISO 6400 / 15 seconds (2 sets - 10 shots each for stacking - Used sequator for stacking)
I used Lightroom as well as Photoshop to build Pano, ended up with the same results. I even tried not setting lens profile, still same issue
Of course, the camera and Tripod never moved from it's place, no even wind gusts.
Can someone help me understand why is this happening? Is there a way I can correct it in my process?
It's probably confused by the movement of the sky wrt to the arch. You might need to manually align or use a different alignment method such as a dedicated panorama program where you indicate points that need to be aligned.