The Lightburn Camera Mount (purchased or 3D printed) pivots or swivels longitudinally.
After (or before) calibrating the camera, how does one get the “pivot” of the Lightburn camera (in the mount) to be perpendicular to the cutting surface workspace?
If it isn’t perpendicular, it distorts.
For example, I have engraved crosshairs on a jig.
If I move the cursor using the “Set laser position” (Alt-L) feature, and place it directly over the center of the crosshairs, it does not move the laser head directly over the center of the crosshairs (so that if I would pulse fire the laser, it does not hit the center of the crosshairs).
In a recent attempt, for example, the laser tube traveled to a position about 40 cm “south” on the Y-axis of the honeycomb from where the “Set laser position” cursor indicated in the Lightburn workspace after having updated the overlay in the Camera Control.
Would it be possible to 1) Update Overlay, 2) Draw a rectangle corresponding to the outside edges of the overlay camera view in the Lightburn workspace, 3) etch that onto a piece of white posterboard on the honeycomb laser surface workspace, 4) divide that into “thirds” – and use the dimension from the “thirds” as the dimension for my calibration pattern size?
It sounds complicated and shouldn’t be necessary. Camera and lens alignment is about calculating and compensating for these variations of disorientation. What I mean is, on my standard 60Watt OMT laser I have a 90 degree LB camera mounted in the lid. Of course I have tried to have it placed in the middle of my work bed, but it still isn’t. Before I calibrate my camera I adjust it in the preview window so that my bed is covered. Here I change the angle of the camera body itself a little, knowing that it is not perpendicular, but it doesn’t matter that much, the calibration compensates for those errors.
What is crucial in my experience is that the actual location/angle and distance of the camera does not change after calibration. A single degree or millimeter ruins the result and the deviation error of the camera becomes too large.
I may have missed the “preview” window and didn’t know that I could make adjustments there. I have the camera attached to the inside / underside of the laser lid. I actually laser-cutted a mount to use instead of the 3D mount. Thanks for your observations. They will no doubt get me closer to the goal.
This is the image from Lightburn’s Camera Alignment Wizard. See the curvature of the lines? I don’t think I selected the fisheye option in the Calibrate Camera Lens utility . . . so it suggests to me that the camera is not directed at an exact 90-degree angle with the work surface . . . and accomplishing that, it seems to me, would be tedious with the lid closed.
OR would this “aberration” be “fixed” once I use the alignment procedure, aligning the lens with the targets printed on the work surface? I know that I followed that routine once, but didn’t get the results for which I was looking.
ALSO, is it possible to MANUALLY focus the Lightburn 8mp camera? Again, this seems like it would be difficult to do without trial-and-error since the camera is only properly positioned with the lid closed.
I’ve toyed with the idea of cutting a “lens-sized” hole in the lid of the laser. I can always cut another cast acrylic piece for the lid . . . but I’m not interested in rushing into things.
If it is before calibration then it is “normal” with a curved image. What “irritates” me a bit about your image is that it should be a larger area of your work surface, it will be adjusted later in the process but of course cannot be larger. That is, if it is the max view of your camera, then your mounting height is not high enough.
As long as you have your entire work bed covered, no matter how distorted it looks, it will be adjusted during the calibration process. As I said, my camera is not placed 100% in the center either, but I have approx. 5cm of coverage beyond the machine bed. On a daily basis I have a deviation across the machine bed of approx. 1-1.5 mm, but with a little fine-tuning, if I need precise placement of letters on a pin for example, then I’m at sub mm level.
Remember to put the height of your test piece into the chart, and when you print/engrave the 5 target discs at the end, you may not move them, they can’t (usually) be reused either.
(On my diode laser machine I have also drilled a hole in the box, but I will not do that on my OMT CO2 laser.)
The LB camera I bought a month or so ago IS capable of manual focus. I got a delightfully clear focus on a queen of diamonds playing card.
But I still haven’t been successful at creating registration marks so that I can use them to align the camera and accurately place a jig for inserting pieces to be engraved.
That’s interesting. Does that mean that your camera has manual focus and you have to fine-tune the lens to your laser bed distance?
I have the impression that mine is autofocus, because I can’t screw the lens in/out and because the image is, in optimal lighting conditions(!), fine with the “random” distance my camera has.
It’s a shame that you can’t get any further with calibrating your camera. If it’s not set correctly, it’s useless.
A lot has happened in the last time/version with camera calibration in LightBurn, I don’t really need/want to test/try it out because my system works very precisely as it is. On the other hand, I would like to test whether the light handling has been optimized, that’s the only problem I have with the LB camera on my Mac/Linux system…
The last time I tested, I couldn’t get LB’s new target system to work, so I ended up using my old test card with the black circles again, and manual exposure handling was still not implemented for Mac (compared to the Windows version)
The Camera Alignment then uses this undistorted image to align the placement.
All (recent) LightBurn cameras use manual focus because the autofocus tends to mess up the lens calibration.
I’m surprised to hear that. In my experience, AprilTags work much better.
I assume, you did follow the hints in the infobox about the correct size of the calibration card?
Also: “It is not necessary to mount the camera in the machine to perform the lens calibration.”
I’ll give it a serious try again.
Do you know if there’s been any work on exsposure adjustment/compensation for the Mac version?, “too much” light is my biggest problem.
I don’t remember seeing exposure adjustment sliders on the Mac version but there have been a few macOS camera-related changes since AprilTags were first introduced in version 1.7.0.
Let us know how it goes if you decide to give it another try!
No, there are no adjustment options, neither in the Linux nor Mac version, which is my problem.
Under normal lighting conditions it is impossible to see what is being cut/engraved. If I want to have a chance of seeing anything, I have to turn off the light. The automatic exposure does not work at all, or very very slow and weak.
Whether it is hardware or software I do not know, but the ability to manually control exposure should be able to solve the problem.
It is noteworthy that during lens calibration and camera alignment, there are no problems with overexposure, when selecting the 4 targets it works (in B/W) quite well, i.e. targets are well visible.
I have made a small video to visualize the problem, as well as some pictures with and without light.
Because I have found my own way to live with this problem (I just turn off the light when I need to use the camera function) I have still figured out how to fine-tune my camera. I have a margin of error of 0.5mm over my entire machine bed, which is fantastic. If I divide the bed into 4 sections I have a precision of under 0.2mm. If only it could also withstand the light of day then it would be perfect
I printed them extra black and it worked fine, it’s just confusing that the documentation during the process hasn’t been adapted yet. (only the old targets are shown in the description)
Consulting the team, I have learned that The Auto Exposure and Auto Brightness switches are available on Windows only — on macOS, Exposure and Brightness are always automatic.
The Fade option in the camera control window can improves things, but I see you already tried this.
In my opinion, this is a problem. How do you manage it in the office/workshop when you experiment and test LightBurn? Or do you run it exclusively in Windows? How do other users of LB with Mac experience it? If there is a trick, I would very much like to hear about it, having to turn off the light to be able to use the camera is definitely not a proper solution and especially annoying, because once adjusted (and the light turned off) it works excellently.
Thanks Aaron for your response, I have also considered the possibility of putting a filter on. Would you be so kind as to inquire at the office about which filter is specifically suitable for our LB 5MP90º cameras?
I’ll try your link right away, thanks.
I have tried the FPS rate, but can’t see a difference, but will test that again.
Any ND filter made for GoPros should cover the entire field of view of the 90º camera. Based on my experience, I would choose an ND value between 8 and 16. I’ve asked the team and will let you know.
Unfortunately the link is over 4 years old and I can’t use the code on my current MacOS 15.4.1, nor do I have enough knowledge to rework the code/tool. It’s a good starting point that LB could take care of…
Here are tests from today with and without normal workshop light, the light in the machine hasn’t even been turned on.
..have found it, does not fit the LightBurn lens, unfortunately. They are far too big. The lens mount on the original LightBurn lamera is approx. 8.5x8.5 mm… and the lens itself approx. Ø 6.5 externally. Have also tried putting filter material directly over the lens on the original enclosure, it compromises the image quality much.
I’ll try it out anyway.
I will also try to contact @barsam and ask him if he has further developed his software solution.
