I have a 60W MOPA, and I am trying to burn an image on SS. But when I enlarge the image so either the height or width dimension surpasses 65.534mm, it will not preview or engrave. I have tried four different images, and 65.535mm or larger will not work. My workspace is 300mm x 300mm, so it more than fits. Any idea why there is a threshold on image size or how to increase it? They are around 100kB files of simple line art with text. Taken from screenshots.
Do you have some limit like 2^16 somewhere?
Which lens are you using? Have you ever done something larger?
Itās written on the lens, such as F100mm. The lens length determines coverage. Mine has an F254 lens for 175x175mm coverage, ā the F420mm is for 300x300mm coverage.
Do you mind posting the .lbrn2 file you are using?
I donāt know where I would impose such a limit. So, not that I know of.
What lens are you using?
My lens is F420. I actually have done images larger than that before. Funny thing. I just dropped the image into a file that I had used previously to burn larger images, and it is previewing fine, now (with different parameters). I did notice that the laser settings have something to do with it, and it boils down to interval. My settings for black images on stainless steel require .002mm interval, but when I increased it to .003mm, I was able to scale the image up to a max of 98.301mm. 98.302 would not work. At .004 interval, 131.068 is the max size. It appears to scale linearly with interval. Iāll try to attach a file with the width set to .001mm over the allowed size. If you change it from 65.535 to 65.534, it will preview. Even very simple images will not work past this dimension, whether it is width or height. Any idea what how to get larger images burn with a small interval?
Mori No.lbrn2 (83.1 KB)
Itās clearly the interval appearing to be the culprit.
These are pretty small intervals, smaller than the machines beamā¦ That might be an issue, mathematically speakingā¦
Might ask @Rick if heās awareā¦ this is sort of familiar, but canāt place it exactlyā¦
Or a Bug? I`m on 1.7.00
Do try the following:
- Change Image Mode to Grayscale and do a preview
- Revert Image Mode back to Threshold and do a preview
- Did preview work?
- Enlarge the image and try engrave
Thank you, Iāll take a closer look. 
Update: Yes, I am seeing unexpected results with Preview as well. Investigating furtherā¦
Update after digging in and further chats with Oz.
We use a cross-development platform called āQtā to build the different versions of LightBurn (Windows, Macs, and Linux). 65536 pixels is the absolute limit of Qtās internal image handling. In this case, the settings for black images on steel are just re-running the same lines over and over again because the actual physical machine is incapable of producing a 0.002mm interval. A 420mm field, divided by 65536 pixels (by coincidence, the max addressable precision with a galvo) gives 0.0064 and change.
Have considered making the image rasterization code smart enough to realize that this is the case and have it just āundersampleā by the correct amount, but thatās going to add complexity and take time to debug.
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