Using a Boss Laser 65W, settings 250speed/12.5 pwr 600dpi and stucki. The image down near the dogs privates looks like a negative type image almost. It’s not clear…I did another one with an ocean and the ocean looked like a negative.
Try about 1/2 the DPI and the results will likely be better - You’ll need to adjust the power up to compensate for it. Without a really short throw lens a 65w tube isn’t going to give you 600 DPI, so you’re likely killing all the mid-tone shading.