Hi Felix,
There’s a good guide for photogrammetry called “Photogrammetry in Paleontology” (http://www.jpaleontologicaltechniques.o … 12_Jul.pdf - essentially all tips and tricks in this guide can be transferred to whatever discipline, so not really limited to Paleontology). The author uses PhotoScan for processing, but a lot of this info is relevant for any photogrammetry suite.
On page 6 there’s a nice comparison between images taken behind glass without a polarisation filter vs with a polarisation filter. Polarisation filter definitely works, just buy one (they’re cheap) and play around.
Concerning “rotating horizontally” - you’re allowed to rotate the camera any angle you choose (horizontally, vertically, diagonally, whatever), just don’t “pan” the camera like you would for a panorama, but instead make sure you move between each shot. From what I can tell from the camera positions in the screenshots you moved between each shot so that’s perfectly fine.
Cheers,
Tom