Hi John,

Yes the tiny number is the deviation in pixels from where you pressed zero.

I don't think it was ambient light affecting your setup, the laser saturates the sensor. It is so sensitive it will easily pick up deflections in your floor from walking about. This happened when I was testing too, I had to sit completely still. It is less sensitive to walking about on a 6 inch bare concrete slab but you can still move it a few pixels.

You don't need a better camera you just need to rip the optics off that one. The difference in quality between webcams of the same resolution is simply the optics.