Images don't work with low interval setting

Hi there,
I try to engrave a b/w picture on aluminium with an interval of 0.001 (worked best in material test and text mode), but only a part of it (or nothing at all) gets processed and engraved (however, at the right position). This also applies for previews (see screenshot). If I increase interval value, it starts working correctly at some point. I tried a smaller picture (500x500px) and got the same issue, but a little later with the interval being decreased; so it might be memory related?

Any help is appreciated!


(Lb 1.4.01 on MacOS 13.5)

You didn’t mention any specific lens… but most lenses spot sizes are in um or microns.

The smallest spot size for the F100mm F-Theta lens is between 10um and 12um or 0.010mm to 0.012mm according to this Cloud Ray chart of Omega lenses. The coverage is the number before the F number… An F100mm has the coverage of 70x70mm… Shorter focal length, smaller dot (spot size) shorter depth of field.

The value you want for an interval is 1/10th the size of the lasers kerf.

I can’t see how, you are making ~10 passes over the same area…?

It is also smaller than can be reasonably expected for applications such Lightburn to operate, so an issue like this wouldn’t surprise me.

Been down this road myself… trying to fatten lines using a very small offset…

Have you watched the Laser Everything video on photo engraving? It very good and show how to pick the right interval for any laser with any material…

I commonly use an interval of 0.0254, unless I’m trying to do something specific.

Good luck



first of all thank you very much for your quick and comprehensive answer and comments.

You actually got me here: while i did notice the ridiculous values for resolution that should have rang the alarm bell (and probably hitting some limitations of the software for the sheer size), my values merely resulted from a night of running material tests to get some things done…
For some text and the test grids, those values worked fine and returned the best results in comparison – apparently not by physically increasing the actual resolution (I used a F420mm lens).

While I’d really enjoy these settings to work on the fly with my picture as they did for some small stuff, I’ll humbly take your advice and direct my aging brain cells on these tutorials, to try and find the parameters that really represent what I have been doing (and build some fundamental skills)!

Best regards & thanks again,

I have 4 lenses, including an F420mm, for 300mmX300mm coverage… The spot size is roughly 0.05 - 0.08mm, so it’s about 5 to 6 times the size of a shorter lens…

Keep this stuff in the back of your mind and when things don’t work out, it might become more clear to you… :wink:

Have fun, that’s the bottom line…

Good luck


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