If I missed/misunderstood something please enlighten me. I enjoyed typing (and researching) it so much that couldn't stop. What OD should your safety glasses be? Use this calculator (set the wavelength to 450nm-that changes things): OD Calculator Too much soot on the lens will cause it to absorb enough light to overheat and crack. Air assist blows the smoke out of the way, increasing the effective power and keeping the lens cleaner. These particles partially block the beam and reduce the optical power fewer photons per unit of time reach the material. Enabling 'Optimize Z Moves' will prevent this constant retract / plunge behavior, only issuing Z moves when the Z changes. Much of what you do see is the surface of the material burning and the smoke, heated to incandescence, scintillating in the beam. By default, LightBurn will always retract the Z back to the initial height (the material height) after completing a shape with a Z offset. Your safety glasses greatly attenuate 450nm light.

Haden34 wrote: ↑ Thu 1:06 pmlooking at laser while its running with glasses on beam is yellow not blue looks like a fire flame? maybe thats my issue? i really thing laser is defective but i dont know

Atomstack a5 lightburn