I don’t understand what this means. Fast engrave over the already 2-pass engraved part? That’d get rid of the charring, you mean?
@csader is right. Subsequent passes pronounces detail of depth.
So @dan, does this mean that auto-focus is fully operational?
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fancier than “extract more depth” 
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Yep. All you need to do is zap a thin surface layer. (When I was experimenting with 3D engrave on wood before it went PG, I would typically do two passes for depth and then one more very light and fast for char.)
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Oh, I’ve been on it and you are SO correct. But luckily part of my brain still remembers late-90s web 1.0 (I was a “Web Master” back then!) so it isn’t too foreign. 
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Paul… That’s fascinating. Burning more reduces the char?! I’m guessing by some noticeable amount?
When you say light and fast, can you give me some idea of what you’ve used there?
If you want an updated web experience, the Aster DEM data is also available on NASA’s Earthdata site:
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I was just thinking that it looks like a rustic home-made cracker.
Well… the setting was right there!
Perhaps I should have titled this “Deep 3D Engrave” rather than 2-pass, but it’s the same thing. It’s only an option on Thick Proofgrade and I wanted to see what the behavior was. My expectation is that if I did a regular 3D engrave on both thin and thick Draftboard, they would look pretty much the same (be engraved to the same depth) whereas the Deep engrave would essentially exaggerate the terrain by 2x.
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I think what he’s saying is to do a very low-power pass over the whole thing after it’s done, which should be enough to vaporize the char but leave the wood intact without causing more char. I saw this technique mentioned in another thread some time ago, and I’ll give it a try next time. If it works well I’ll suggest that the Proofgrade setting include a “Finishing Pass” checkbox!
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I don’t think this has anything to do with autofocus… it’s creating the varying depth of engrave by continuously varying the laser power as it scans across.
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For a very very rough first approximation, charring is proportional to the amount of time the beam spends in one place. So inversely proportional to speed. (I think that this happens because a very short exposure still vaporizes the top layer, but doesn’t give time for heat to propagated down to lower layers that can burn without being vaporized. Sorta. Kinda.)
My notebook has some numbers I don’t trust, but for the cleaning pass I would start with full power as fast as you can go and then maybe back down the speed if needed (or power if you’re cutting too deep).
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Yes, but as more material is removed, the difference between the lightest (highest) and darkest (deepest) becomes more pronounced, particularly with additional passes - the focus on the deepest part would need to adjust to be optimal I think. 
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Bravo!
The Proofgrade setting incorporates two passes for the best detail in thick material. We still have lots more autofocus work to come, but it’s getting better. 
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Thanks for the info! I’ll have to experiment!
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Any particular brush you have found to be effective without potentially damaging fine detail?
Interesting. I’d say it did a pretty good job!
I just picked up a scrub brush at Home Depot when I went to get the soap. It seemed to work just fine.
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It’s such beautiful texture. Cut it into a bunch of 3 inch diameter rounds and you’ll have fake cookies to hand out for Halloween! TRICK or Treat!
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I’ve used a soft toothbrush for cleaning up fine detail on wood items, and using either rubbing alcohol or acetone won’t raise the grain or cause the finished piece to warp.
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Woah! I never thought we’d reach the point where we might have TOO MUCH detail! That’s overwhelming…and awesome!
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