Have you come across these type of things https://www.aliexpress.com/item/4001351566621.html that appear to behave like a metallurgical microscope.

I'm kind of tempted. I assume the objectives aren't infinity corrected?

Just found - https://www.youtube.com/watch?v=b_IWTq-TSiU which shows something similar. It looks like there's a ring that seems to adjust magnification on it, unless I'm mistaken.

I've got a DIY XY stage and would like to attach something like that too it, to image large objects (I've got a BHM microscope but the stage has only a small degree of movement).

Edit: Just noticed the objectives used are infinity corrected