this revives my recurring desire to get a good USB microscope. Good, to me, in this context:
a few hundred bucks
able to look at microbes
also able to look at less micro level stuff, like maybe the thing i'm trying to solder or fix
is it wrong to solicit comments/recommendations here?
Perhaps better to ask here: https://www.reddit.com/r/microscopy/. They get that question a lot.
Some random ones I've encountered (less for PCB work though):
I'm in the process of building one myself. Take what I'm saying with a massive grain of salt, but I believe you basically need three things - objective, tube lens and a camera module.
If I were you, I would probably buy a normal microscope that supports a microscope camera attachment, instead of specifically looking for USB microscope. There is a lot of misleading marketing around USB microscopes, a lot of them are literally just doing digital zooming in (I have a 30€ "1000x" microscope from Amazon which is nice for soldering and such things, but these fake microscopes appear even at higher price ranges). Treat anything >1000x for light-based microscopes as a red flag.