I did another experiment. I took another computer, installed a test version of the program on it and specified different equipment. But the preview has the same problems.
I also sent an email in which I attached a file with this image. This was a few days ago
Therefore, if we follow your logic, they should disappear or be different, but not be identical, because the equipment is different and Lightburn no longer knows for sure about the capabilities of my equipment
Anything above this post takes away from the essence of the issue. The only thing I’ve included in the post below are questions that people have had trying to help me with my problem.
Equipment:
laser: JPT 50LP
Control board: JCZ Fiber Lite (bjjcz 32101lv)
Sino-galvo SG7110 scanner
OPEX F-theta 163 SCan Lens (working field 110x110 mm)
Software version: LightBurn 1.7.03
All experiments were carried out only on this equipment and in two programs: Lightburn and EZСAD
If you want to discuss the fact that I use high resolution and that my equipment does not support it. Please do not do it. Here is the specification:
Below I will explain why this is a wrong approach.
Also, I say in advance that the resolution of the original image does not affect the result. Also, the image format (jpg, png) does not affect the result. Many experiments were conducted. I wrote about some of them in the messages above.
I just don’t want to repeat these questions.
The file I used in my research:
test 00.lbrn2 (1,3 МБ)
The process of creating a research file:
I created a 3D model from scratch:
From this 3D model a grayscale height map was obtained:
After that I loaded the grayscale height map file into Lightburn and prepared a working file:
When zoomed in, the height map looks great, without any artifacts:
Now let’s look at what grayscale engraving is:
The image is engraved by changing the output power as a percentage between Min and Max Power, using Min Power for the lightest shades and Max Power for the darkest.
When you open a file in preview, the dark areas are what are engraved with more power, and the light areas with less.
Let’s move on to our file.
Open the image in preview. engraving at 90 degrees
In the picture, I have highlighted some places in red, light stripes are visible. Based on what was described above about engraving in shades of gray, light stripes indicate that the engraving in these places will be weaker.
These light spots should have been the darkest according to the drawing.
Now let’s see how this will manifest itself when engraving on metal:
As you can see, these light areas that were in the preview also appeared during engraving. But these lines are not in the original file.
Now, let’s do another experiment.
Let’s change the engraving direction to 0 degrees.
Look at the preview and the finished engraving. I marked the problem areas in red. And the picture of the artifacts has changed:
Now let’s conduct the third experiment.
In the third experiment we will make 3D engraving using the 3D Slicer mode:
This was done with the same parameters as the grayscale engraving of the same image.
As a result, we see the absence of any artifacts that appeared during engraving in shades of gray. From this we can conclude that the resolution of the drawing, the density with which it is engraved, the features of the equipment, etc. are not relevant.
Now let’s make an engraving in shades of gray with the same parameters in the ezcad program
Get the result without the above artifacts:
This also indicates that the problem is not with the hardware or files.
Let’s do one more experiment.
I took three objects and made them with different fills.
The first object is a simple transition from light to dark. As we can see, there are no artifacts either in the preview or during engraving.
The second object is a complex fill. From light to dark and back to light. Here, artifacts in the form of vertical stripes begin to appear, but they are weakly expressed.
The third object is a more complex oval fill from light to dark and back to light. It contains the largest number of artifacts, which are clearly visible during engraving and are clearly visible in the preview mode.
I hope I have given a detailed overview of the problem. And I want to get an answer from the developers: how can this problem be solved?
In recent tests I made I noticed that the “boxes” only accepts and only takes effect 3 decimal digits. In before release (1.4.03 have to confirm) albeit not showing the digits they were accepted and take effect (much more digits) and (I hope there hasn’t been any internal change to the code), so I’ve asked you to do your tests with version 1.4.03 or 1.6.03.
But edit your new settings (device and others) manually and don´t make an export /import bundles so as not to “transport” something from old prefs.
I forgot to tell you. I conducted these experiments with version 1.4.03. on another computer, without import. The results are the same. I think with other versions it will be the same. My settings do not affect the preview. And as I showed above, what is visible in the preview is what we will get on the metal.
Have you uploaded a file so others can check how it looks in their “preview”, and/or try modifications to fix on their end?
Your projects are very detailed, and your laser application is very different from mine, but there is no shortage of people working with grayscale mode and not experiencing this issue, which implies that there may still be some difference in setup that could be identified if you let others experiment with it.
I’ve seen your posts, but I don’t recall seeing a file shared?
reread from this place. I described everything again. There you will find answers to all questions.
Thank you
Yes, read.
Yet again, if we create a close analogue to your problem, we don’t experience the issues.
The simplest way to diagnose something that’s different from your use to our use is always to compare your program in our settings. Otherwise, you’re requiring mechanics to fix your car over the phone.
For example, you even showed tests with simple gradients. But we generally put simple gradients in various sizes, resolutions, etc, in grayscale and do not experience such artifacting.
Sharing a simple file that displays such a problem, and allowing others to test and tweak is consistently the best way to find fixes, and I see others solving their problems on this forum every day in that manor.
If no one else can get your file to work in their system, then we can conclude that it is just a limitation of LightBurn and requires software fix. But I’m skeptical of that, simply because the issue seems to be specific to you at this point.
This is not only a problem with this file. Here is another example. And I tried it on different computers and different versions of the program. The result is the same. I have prefixed the file. Anyone can download and check it.
The first screenshot is a preview, the second is what the file looks like. Artifacts are visible inside the large flower. This will be visible when engraving.
I have already found many problems or limitations in Lightburn. The developers agreed with some and promised to fix them. But this will be in version 2.0
Some are still unanswered.
I am starting to clutter up the post again, proving that the problem is not in the equipment, not in the settings, etc.
When i was trying to debug another galvo issue, I did note that some numbers were stored as floats where kinda inappropriate. e.g.
“CutList”: [
{
“QPulseWidth”: 12,
“angle”: 45,
“floodFill”: true,
“frequency”: 50000,
“index”: 0,
“interval”: 0.02500000037252903,
“maxPower”: 100,
“maxPower2”: 20,
“name”: “C00”,
“priority”: 0,
“speed”: 4000,
“tabCount”: 1,
“tabCountMax”: 1,
“type”: “Scan”
},
the interval here was supposed to be 0.025. I’m not saying this is related to your issue, as even at the fundamental limits of the galvo, this is an error on the order of 10^-9. It’s more that I could see that a compunding error in the hatching algo for grayscale could cause something like this, especially at the DPI your dealing with.
Another question. What are you open MO settings in EzCad/Lightburn? It’s not a particularly well documented or often discussed part of galvo stuff, more set and forget. In 3d slice mode, each pass is done at the same setting. In Grayscale, each line segment across a gradient is a different power setting. When PWM is the control, it’s not really a problem as it’s pseudo analogue at the frequncies in question. MOPA is a different beast! I suspect that the changes between power setting in subsequent line segments are at the timing limits of the MO being stable, or something similar. i.e. not getting enough time to stabilise at the specific power/frequency before changing again, causing a kinda feedback or a jittery signal to the PA parts.
A question to your question, lol: If you carefully read the post I wrote above, these errors occur only in lightben. in ezcad they are not. This is the first. Secondly, as I wrote above, I installed this program on different computers and different versions. I entered the settings manually, made different imaginary equipment. Which is in no way connected with mine. and always in preview mode I get these artifacts. I just did not describe it otherwise the post turns out to be long. I am 99 percent sure that this is in no way connected with my equipment.
And now the question itself: how is the preview connected with my equipment?
Here is another picture: on the left is the preview, on the right is the engraving.
Problems with the preview = problems with the engraving.
Unfortunately, everyone misses this. Of all those who wrote here, except me, only one paid attention to this.
Tell me, how do you debug problems with the program?
Thank you.
I appreciate that you have concluded that problems with preview correspond to problems in engraving. I’m saying this may not actually be the case; With a tight dpi and closely stacked lines, these resemble moire patterns. If you drop the interval down to 0.1, then look at it in preview where you can see the individual lines, there is no problem. If you then zoom out, you will see patterns appear, again in the same areas. How do you display 3 overlapping lines in 1 pixel? Depending on the approach taken, you can end up with different results. To prove this to yourself, draw a basic rectangle in fill mod, with e.g. a interval of 0.01. Open up preview, zoom in . At some zoom level you will end up with something below. If you engrave it, does it come out looking like that? no.
In the watch face design and the test patterns you have designed, the part where problems occur in the physical engraving show up at the points of highest rate of change of cutting power. The preview with power shading enabled also shows defects at the same place, but I think it’s more related to the algorithm determining how lines a drawn on the screen in the preview window (i.e. thicker /darker lines for more power).
In EzCad do you have identical MO settings, including “laser leak handle”?
Maybe we need more internal resolution.
But I have a strange thing happening, I did a preview of your project file (90º) and I´m not getting artifacts.
As I don´t have a fiber but have a fiber device for testing purposes, may I ask if you can share your JCZFiber.lbdev, markcfg7 and COR files so that we have the same configuration?
Also, for debugging I use strace/ghidra/wireshark/diffing config files/a scope/a hammer, depending on where I think the problem is. Sometimes all of the above at once!
markcfg7.txt (10,2 КБ)
Strange and very interesting.
@Colin gives a 64K hardware pixel count, so a lens with a 110×110 mm field has a resolution of 1.68 µm/pixel.
The watch faces are a little under 28 mm OD, for about 16.7 k resolvable pixels.
The 0.025 mm scan interval puts 1120 parallel scan lines across each watch face.
Adjacent scan lines are 14.9 resolvable pixels apart.
The scan lines will be 15 pixels apart for nine successive scans, with the next scan at 14 pixels, for 149 total pixels for 10 scan lines. That will put a misplaced line every 0.25 mm, a total of 112 glitches across the face.
Misplacing a single line by 0.025 mm may not be noticeable, but some of the pictures show visible laddering at about that interval.
Which does not account for the ridgeline effect on those grayscale areas, but does show “high resolution” can become surprisingly gritty down at the physical pixels.
Your test00.lbrn2 imported the shapes with a width of 29.1 and 1000 DPI.
Changed to 26,7 and 2000 DPI and here is the preview (no artifacts):
At this magnification the artifacts are not visible. They are visible to me if I make the image smaller
But in the first images you had it on a smaller scale and I didn’t notice it there either.
But for me it looks completely different and matches the engraved file.
As I said, it’s moire patterns. Try it on an 8k screen!(lol).
