Bare with me please, I’m still trying to wrap my head around the often confusing topic of compositing
Just when I thought I had finally understood how to setup compositing for creating the illusion of a 3d obj in a photo.
Everything seems to have worked, except for the fact that the 3d elements end up showing in a different location as that of the one they show in the camera (I only have ONE camera in this scene!).
Ok, I did a test with another image, just a grid, as viewed from the camera perspective. And both positionings matched. However when bringing back the beach photo the problem came back too.
Newest Update:
Mystery solved! By yours truly
That new position after rendering was simply because I was not rendering at 100% (rolling eyes)