Hi, I tried to process an image ( photo) in Lightburn. I have done it many times however this is the biggest physical size I have tried and it appears that Lightburn can not process the whole image. When I increase the physical size of the photo ( image) beyond 14" x17", Lightburn starts to only allow most of the image but cuts off the top. The bigger I make the image in the file, the more of the image gets removed. When I send it to the laser ( Thunder Laser Nova PLUS), the file sent from Lightburn says it is 225,000 kb, and when I process the engrave on the laser, it only engraves part of the image - it appears that Lightburn can only process a certain amount or size? The actual cut off image is reflected in the “Preview” window. Can anyone provide help or info? Thanks! GP
I would like to confirm the way in which your controller is receiving the file from LightBurn, send or start?
Are you using an ethernet connection or USB?
Can we see an example of your preview window?
How full is your controller’s memory? It may need clearing:
This is the machine code emulation, so Lightburn isn’t generating the code.
Can you post the source (.lbrn2) and a screenshot of the preview screen?
Hi thanks for helping me. To your questions:
- I “Send” the file to the laser from Lightburn ( Always).
- I am using an USB connection ( without issue for months from my Apple Computer)
- Preview Window Screenshot attached
- Lightburn file attached
- Yes, I cleared my memory - and have also deleted and re-sent the lightburn file several times.
Thanks - let me know what you think :))
GP
relief image working file_2.lbrn2 (981.1 KB)
Yes for sure - thanks for your help. Let me know what you think.
GP
relief image working file_2.lbrn2 (981.1 KB)
I just tried your file and got basically the same results. I opened your settings and saw your line interval is insanely low @0.025/1016 DPI. I bumped it up one arrow click to 0.035 and it completed in the preview. I realize you have an RF tube, but I think it’s just too much resolution for an image this size. If I shrink the image it completes at 0.025.
The interesting thing is that while it doesn’t complete the image it goes on to the cut layer after the image.
Hey Tim thanks so much. Thanks for checking that for me - I did not think the resolution would not allow the file to complete(?) in Lightburn? The laser will go to 2,000 DPI, and perhaps you are right - I don’t need 1,000 with such a big canvass. I have always used high resolution for my image engraves, but have never done one this big physically.But I still have the question of why Lightburn would not process the whole file - there was no error message or anything. it send the file as normal to the laser but just of course, not the whole engrave layer.- do you know if there are restrictions on file or other size, ? Thanks again 
GP
I don’t know if there are any posted restrictions on file size, there might be. I know it took a pretty long time calculating before even opening the preview. I’ve seen it actually freeze the program when people try to use offset fill with a complex design. I imagine this is something similar, just too much to compute.
I would expect there to be a warning or error of some kind too if it’s unable to compute the entire image.
Thanks Tim, I appreciate all your help sir. I will see what the Lightburn Techs say as well - thanks again - have a nice 4th of July!
Cheers
GP
Any laser, resolution is determined by spot size. If you have a 1" spot, the best dpi you can possibly get is 1 dpi. That’s at the laser end, the material damage has to be able to withstand that resolution.
Do you know the spot size?
It’s good to know, helps you determine interval and helps you sort out what’s happening to the material.
There are on-line calculators that will quickly figure it out for you, here’s another one.
You need input beam size with a lens and you have to find that out for your source.
That is super helpful Jack - thanks. According to Thunder, I can achieve the 2000 dpi using a 1.5" lens ( which I have). But I will check out these links you provided - thank you so very much for your help. I am waiting for an answer from Lightburn folks, on why the file did not code(?) or complete properly but this is really helpful to me. Always so much to learn on these lasers. I sti :)) Cheers! GP
I’m sure Thunder will give you beam size information. It would be wise to ask for the source manual, that way when other questions come up you have some kind of reference without bother them … I’d even like to browse it 
To make 2000 dpi, you need a maximum spot size of ((25.4mm/inch) ÷ (2000dot/inch)) = 0.0127mm, that’s 12.7 microns, smaller than my fibers shortest lens (16 microns) so I am, respectfully, dubious of that claim. However I’m open minded 
Good luck, hope they can cough up the source manual for you.
Ruida controllers have historically had a 128mb buffer, so any large -ish engraving with the DPI too high would overflow it.
At 1000 DPI, a single square inch is a megabyte of 8 bit image data. In Ruida commands, it can be significantly higher - 3mb for a 50% dither. at 2000 DPI, that’d jump to 12mb. A 1” x 10” image could max out the memory of a Ruida at that DPI.
Higher DPI often means a worse result in laser-land, especially if you’re using a CO2, as the beam has a thickness, and you end up just running several lines on top of each other, which produces dark, muddy results.
Here is some more info about image engraving:
And the specs of Thunder controllers:
https://support.thunderlaserusa.com/portal/api/kbArticles/699847000000325504/locale/en/attachments/ktgtaf84d91d1f31a4375ac2dfcc968b37f5e/content?portalId=edbsne84c65c819d39967d3e17abb6582aec59ab41c30231e56f22e81964873293331&inline=true
Doesn’t grayscale mode also load it up with lots of code? It would have to change it’s power setting to do that, I would think.
Thanks very much for your help billie. I will take a look. I am getting some very helpful info on why the Ruida controller may not have liked the file, so to speak, but still, I need to figure out why Lightburn would not process the full file. Thanks again and all the best!
jarvis is usually alot better for images and might actually work with his image. grayscale images end up being much to large and you overflow the ruida quickly on a 8in round
Sorry to say what I mean - as photographer I had many times to decide on high resolution - needed for super images in printed books - with laser it makes no sense to use a resolution of (for instance) 254 dpi - that means 10 lines or points per millimeter - that is far to much and no graphic or photographic vision - it only smears
Hey thanks - I will run it again at the lower dpi and see how it turns out - thanks for your help. Cheers!
Actually when we generate the preview, we’re generating the machine code as well - we just direct it to the preview window instead of to the device So if it can make a preview, it can make the gcode/ruida file output. The question then becomes what the memory limitation on the laser is…