Hood,
The resolution is in the .001's, take a look at my post in the topic"anyone know where to get an optical edge finder?" it is reply #44,
I have a actual screen shot picture there of a mm scale, the resolution can be seen very well, I think you can even call the resolution in the .0000's.
With proper lighting you may be able to get the camera a little closer than in that picture.
Arnie