Given all the folks engraving photos recently, thought maybe a old 1800s lithograph might engrave better since it is linear shaded.
I chose this one as it was high-res and nicely shaded
Engraved it on 1/8" Baltic Birch:
Chose the medium and dark settings from Maple Ply, I may try a midpoint to see if I can get more contrast without baking the wood. Definitely does a pretty nice job, although the darkest areas get baked on the darker setting, while the lighter one has way more subtle detail, it kind of fades. Also might try this on hardwood which might look better.