Ha, it looks to be about 1/4" deep in the photo, so some optical illusion going on.
So is it possible to produce something with strong shading with going deep? It seems like you should just be able to burn the surface to make it go dark without going deep. Or is that exactly what this is but the artistic effect makes it look 3D?
Interesting test, thanks for posting it. (I have the same image saved, now I can knock it off my āto-tryā list lol.) Being that itās such a tiny engrave, Iām pretty impressed actually. Iām a total laser noob too so Iām trying to wrap my head around how the machine interprets shades of grey. I understand how LPI settings on the laser effect the depth/burn etc., but how much does the resolution of the initial file effect things? If you take a really low resolution download and scale the image up, how much does it degrade the final laser outcome?
I keep telling people 3d engraving is just a function of power and speed. They havenāt dialed in the settings for it yet to allow for an automated experience, but doing it manually works fine.
It is supposed to do multiple passes focusing deeper and deeper.
It definitely does. Automatic would be a LOT easier. To me, to be able to do it properly manually youād need to separate each depth and then engrave each of those one-by-one setting the power/speed to your tested depths. I imagine doing your deepest engrave first, then going up layer-by-layer. Or maybe Iām over-thinking it, but it seems the only way I can think of to do that manually.
I think you need to do the shallowest first so it is out of the way when you do the deeper ones if you are doing it layer by layer.
To automate it I think you need a raster image with greyscale for depth.
All the 3d engraves Iāve done were with depth maps and didnāt need multiple passes unless I wanted the difference in depth to be more pronounced. It was just a single pass standard engrave.
Perhaps. Although if youāve removed all other layers from each other, it shouldnāt matter either way since thereād be no overlap.
Yes. Thatās how 3D engrave will work, but thatās not been my experience with Engrave By Color which has been all shades are virtually the same depth (yes, with some minor variances).
Yes but you can go much deeper if you remove the top layer first and then focus lower to do the next layer down and so on. Each pass only has to remove a very thin layer and you can go as deep as the focus will allow in any material.
But each pass would be its own depth, not a portion of anotherās depth. So one pass would be 100% deep areas, next pass 75% deep areas, then 50% deep areas, then 25% deep areas. Each is independent, so order is practically meaningless.
The other day I got a .75" engrave on a .85" piece of wood in a single pass. It wasnāt pretty, or detailed. I could have gone slower and possibly gotten deeper but, frankly, it was a dangerous engrave. Definitely saw fire and watched it every single millisecond, ready to open the lid.
Yes or you could do them the way I suggested using the same power each time but a lower focus. Say 10% removes 1mm. If you then run it again focusing 1mm lower it will take of another mm and so on.
Or you have to find powers that will do 1mm, 2mm, 3mm etc.
And thatās what Iāve been doing.
I suppose. But I donāt think the focal range of the beam is that diverse. I could be completely wrong about that.
If say 10% power takes off 1mm from the surface then running over that 1mm pocket again with the focus 1mm lower should take off another 1mm (assuming no build up of ash).
I donāt even know that focus would have have that huge of an impact, as far as variable focus goes. Or maybe Iām just stuck on the concept of camera focus in that focus is 3-dimensional and that for a given focal point you have an acceptable amount of sharpness front and back of the object where the lens is focused. I understand the concept of beam convergence and where the laser beam is narrowest (sharpest) but that has a depth component attached to it. Of course, this is why some laser systems have different focal length lenses that can be used, I suppose. A longer focal length laser lens will have a shallower rate of convergence/divergence beyond the focus point.
If you focus 1mm lower onto an object that is 1mm lower then the beam should hit the surface with exactly the same energy density, i.e. the same spot size. If you keep the focus the same the lower surface will get hit with a slightly larger spot with less energy density as it will be slightly out of focus.
I am not sure honestly, from what iāve seen of the default settings, the darker something is the deeper it engraves. I imagine you could set the laser for a lower power setting and slower movement and possibly burn shallow but still dark, or possibly multiple quick passes. I havenāt tried yet.
Iām not disputing your logic. I just think the workflow I described might be easier for manual 3D engrave until the ārealā 3D Engrave option is turned on.
I agree in theory but reality may be different. Time will tell, I suppose.
Well to focus 1mm lower with a laser you just move the lens 1mm lower because the incoming beam is parallel. So if your material is 1mm lower then moving the lens 1mm lower will give exactly the same effect. The fact the beam has travelled 1mm further to the lens makes no difference.
I agree with that.
What Iām uncertain of is if it (refocusing) will make an appreciable difference in the end product. I understand that you deal in specifics and exactness - that the exact same energy may not be delivered at the specific material depth on a subsequent pass doesnāt mean the end result will be unsatisfactory.