Hi Guys,
I only use the laser pointer on a router where precision is not an issue however, a polarizing filter is still essential. The actual beam width, as far as I can measure, is 0.3mm but our perception of coherent laser light is something different. The surface finish of the work is a determining factor here and highly reflective surfaces produce a sharp and fine image whereas sawn wood produces just the opposite. On Traffolite, engraving laminate, I am confident I could achieve a repositioning accuracy (on an engraved line or edge) of better than 0.2mm.
In reality I align my router work to a pencil line (how accurate is that ?) but this laser device saves so much time and makes positioning so easy that it is now an essential part of the machine.
Tweakie.