I’d like to experiment with rastering a (TBD) photo on one of the lasers. I’ll probably start with the Zing; partially because it’s in lesser demand, and partially because I was able to read the manual and discover how the Epilog people recommend using their dither settings to do this.
So … my primary question … has anyone done this and did you do anything specific to prep your image first? I’ve read other things online that describe various photo manipulations that may (or may not) be useful for a better output.
Here are a couple of examples of photo raster images that I had done on Alyssa’s laser (the one she loaned the 'Space until we bought our old Full Spectrum laser…).
The only thing I did to prepare the images was tweak the lighting and contrast to get the amount of detail that I thought would work best. On the second link, you will notice mention of different raster types… Those were preset options available in the software that was used by the Full Spectrum lasers. In those examples, I used the same (already “tweaked”) file for each of the three types of raster available in that software… I haven’t tried to photo raster on any of our current laser cutters, so I can’t really say what the approximate raster settings would have similar results…
Hopefully others have, and will be able to provide more detailed answers for you. 
My profile pic in grayscale rastered on brushed silver & black two-ply plastic… Was just testing various options on the laser cutter and liked how this came out.
Several different grayscale images with varying degrees of shadowing and details rastered on two layered plastic. In addition to the original one of me (in the center), there are three sets of the images… The more solid sorta artsy looking ones have ‘no dither’, the sorta smudged discolored ones used ‘simple dither’, and the most clear from a distance ones used ‘Halftone dither’. Each method definitely has its advantages and disadvantages… 
- Edited to upload the images and information about them, since the links to the image pages erroneously showed up as broken links…
