Bought a cheap wet tile saw from Harbor Freight. Black Granite 12X12" is $3.80 from Home Depot. Also bought a cheap sandblaster gun from Harbor Freight for finishing the sides of the granite to remove saw marks.
The exercise was as much about preparing the image as it was doing the engraving. The image is actually four images that were layered and graded in intensity to give the effect I wanted. Not too bad. I think I can do a little better though. The hardest part is learning what the minimum and maximum shading levels will look like in the final output.
Images: Google images
Software: Adobe Photoshop Elements and Corel Draw 12.
Controller: LightObjects DSP, DC 40W laser
Subject matter is a 1912 Photo of Albert Einstein. Behind the portrait is his original text from his notebook describing the general theory of relativity. On the lower portion of the image we see some other notebook scribblings and the english text translation of his theory.
35W laser at 40% power 400mm/sec