I’ve been trying for months to get this Sculpfun cam500 to perform a lens calibration with zero success, and I’ve watched Lightburn’s video, as well as, dozens of other YouTube videos, and all I get are very sporadic results. I have excellent lighting, and if I can figure out how to attach some screen captures, then I can show some of my recent results. This lens calibration doesn’t even act like it does in Lightburn’s video on the subject. I’m at my wit’s end trying to get this perfectly good camera to act like a usable camera, but Lightburn isn’t even trying to play nice. How difficult should it be to capture usable images from a camera? The camera is at the middle of the bed and at 33cm as specified by the instructions, and I have Windows 11. And, if it matters, I have an Atezr L2 24W laser with a 410*410mm capacity.
You can drag-and drop images to the form editor to attach screenshots. Alternatively, push the upload icon in the form editor toolbar to get a file dialogue where you can select images to upload.
I didn’t get any kind of toolbar on my initial inquiry screen, otherwise; I would have figured that one out for myself. Thanks for the info though.
I think you have your origins back to front. Your capture should look the same as the camera view. Its like 180 out. Also once you sort that out Watch this vid https://youtu.be/yomtRqT1tU4?si=_duBI2VEP59xU-rS
A few tips:
- Paste the calibration to a known flat surface like poster board or MDF. Any slight waviness in the material can compromise the calibration
- Do the lens calibration away from the laser where you don’t have anything else in the immediate view of the camera
- You want to avoid any harsh lighting situations and shadows. Bright diffuse light is ideal.
- Hold the calibration pattern by hand so that you can fine tune the angle and position of the card. The slightest changes can result in drastically different capture results
- Disregard the captured image and only focus on the score to determine a good capture. Ideally you’d be in the .3 or less range for capture results.
This does not really matter. The 180 degree turn of the image is done later through the image alignment process. The camera position can be any (0, 90, 180, 270 degrees).
Though, it might be worth trying to move the calibration pattern as the algorithm visually requires:
If the wizard asks to put the pattern to the front, put your pattern to the back of your workspace, such that the algorithm gets it at the front.
Ok so it doesnt really matter but it’s does. Really ?
For what it’s worth, I have tried to do it with the pattern in the 180-degree position with no better results than the other way around. I have the image pasted to card stock, and it sets flat on 16x16 plywood as flat as it can be. I’ve tried the hand holding with as much luck as sitting it on the plywood, which is to say that it doesn’t do any good to hand hold the target. I don’t see how the lighting could get any better, because I’m using a 16 LED shop light pointed at the ceiling, and I move it around to light each position so that there’s no glare at all. The scores are so radically varied that there doesn’t seem to be any logic as to why it can’t get a usable score. This so frustrating, knowing that I can see it being done in a video, but I’m not able to get it to work. And what’s really got me annoyed is the fact that I’ve been working in IT for the last 15+ years, and I don’t normally run into these kinds of issues. I also know quite a bit about programming, so I would be very curious to know what this algorithm is actually doing. It seems to me that this process could be done much better. You can go ahead and close this ticket because I’m not going to be wasting anymore brain bites on this matter and I’ll be returning the camera. Thanks so much for taking the time to respond to this request for help.
Look up OpenCV Camera Calibration to get an idea. LightBurn uses OpenCV internally to do this. In fact, you could potentially do the lens calibration outside of LightBurn if you were so inclined.
If you’re going through the trouble of returning the camera, I’d suggest attempting the calibration outside the laser if you’re unmounting it anyway.
I wish I had the time to pour over thousands of lines of code to try to figure out what that calibration function is doing, but I honestly devote way too much time on this laser engraver. It was an impulse buy, and I really don’t have the time that most people on YouTube are devoting to the art of engraving. I’m really impressed with Lightburn and what this laser is capable of doing. I’ve been an avid photographer since 1982, and I’m really liking the quality of engravings that I’m able to get from some of my analog (film) images.
I only brought it up since you were showing interest. Note that you wouldn’t actually need to look at code to get an understanding. There is plenty of documentation, examples, and existing examples/utilities with some very neat real-time pattern recognition type of stuff going on.
What I wanted to say is that the camera angle does not affect the functionality of the camera alignment feature. It works in any of those positions.
Though, the lens calibration function might not be rotation-independent, and therefore it might be worth trying to move the patters as I suggested. Due to the size of my workspace, I mounted my camera turned 180 degree as well. It worked fine every time, but I don’t remember how I calibrated the lens back then.
Sorry didn’t mean to be snippy but clearly the direction matters. For what its worth I have a new camera coming and I will be aligning it and I will try and get it 180 out just to see what is what. If you y get my drift.
I’ve tried it in both directions multiple times and neither way has produced usable results. But I’ve since returned the camera and may try again with a different camera, but I really have a bad taste in my mouth from the whole experience. Do you know anything about the Mintion camera? I’ve heard people who use an IP based camera. Do you know if it’s the same process to install an IP based camera?
I’ve found the information at (Using a camera with a diode laser - Diode Laser Wiki) “At LightBurn LBX it was announced that the camera features get a major update soon. Calibration and all related stuff will get much, much easier. Looking forward to seeing it!” But I don’t see a date for the information. Do you know if this is current information?
Courtesy of someone that spent way too much time dissecting the OpenCV library:
OpenCV is a highly optimized library with focus on real-time applications.
OpenCV is built to do real-time computer vision, not precise measurement. This means that OpenCV prioritizes speed over precision. There are many applications where this is the right choice. But there are applications where it isn’t: in my line of work, precision is important.
When you hit the graphs, you’ll understand why the camera will randomly be off one day, or why the camera image will never quite line up properly to what was actually cut on the laser when you move from one side of the working area to the other.
I already calibrated the lens on my L8 and saved the settings. I have been using the camera. Today I went to use it, and I had to start all over again. Is recent update the culprit? Eventually I got down to about 0.5, clicked next and nothing happened! So, I am stuck. I can proceed without the camera but for some things it makes it so much easier. In my case I use it to cut out stick on labels.
I foud that printing the calibration dots on a full A4 sheet helped a lot
My camera is working perfect in windows 10 under the operating system, but as soon as it goes into lightburn it looks great until i update overlay, then it mirrors. I tried to go back and reinstall my camera and it won’t get through the first steps. I think something changed in 16.0 I’ve got another camera being over nights I’ll know more tomorrow. But as of right now I’d say something isn’t going Good with the 1.6 update. I’ll try to get some pictures as well. I hope these images help. I’m not great or even good with lightburn, but iItry. I’m using an xtool D1 20w and a comgrow m8 camera, on an alienware 15 R5 laptop. Hope I covered everything. Would be nice if xtool would give some instructions.
This is typically caused by incorrect ordering of targets during the camera alignment phase. You must identify targets in numerical order. LightBurn will use that information to correctly orient the overlay.