Eli5: how do stud finders work?

Question

Title

In: 33

Answer 1

Not very well in most cases. Knocking, using a level or other straightedge to find butt joints, using rare earth magnets to find screws, or looking for shadows is way more effective.

edit: you can come at me, but every experienced tradesman I know, myself included, can find studs faster, more reliably, and on more different surfaces (eg: not just 1/2″, 16″ studded drywall) than any finder on the market. But most of us still have one or two.