I am trying to setup my camera with LightBurn. Nova 63, 120 degree Thunder cam. Attached is a photo of what I get. Is there a correction for keystoning? The test pattern print out as it should. I imported the preferences for the thunder cam with the 120° lens. The laser lines up on the test pattern as it should when I use the positioning tool however when I get to the outer edges or the top the positioning of the laser is off. I believe if there is a keystone correction this might solve this problem. Any ideas?
From what I can see it may be working correctly. The target material looks fairly square.
The top of the gantry is not at the same height as the material and is at the very edge of the image so will not necessarily look correct in the capture.
Can you try moving the gantry out of the way and placing a square piece of material at the proper focus distance nearer to the top of the bed? That should help you determine if you’re still getting distortion.
One thing I’ll advise is that your alignment targets are fairly close together compared to the size of your bed. You may want to burn those at a larger scale to fit a big part of the bed.
That will help reduce the impact of any alignment errors.
I moved the gantry to the home position in the upper left hand corner. Attached his a photo with a square piece of material above my target test. Is the curvature at the top of the overlay a normal condition or am II doing the alignment test wrong?
LightBurn will attempt to correct for lens distortion in order to make basically an orthographic projection onto your workspace.
I can see now that the correction is too extreme at the top even at the proper distance to the lens.
Did you run a camera calibration? Or are you using the preset calibration?
If you ran a calibration what types of scores did you get?
As for alignment, what I was suggesting was to increase the scale of the targets so that it fills a larger portion of the bed. That will help with alignment accuracy. But you’ll want to address calibration first.
If you haven’t already, make sure focus is as good as you can get it at the distance to the material.
I calibrated using the preset 120_cam_lens_cal.lbcm provided by Thunder for this camera. Here its a pic of my focus. I did try the connect the dots focus and the score were always “Great!”, however the accuracy on the test print was way off. Also notice how Picture in the camera control photo does not necessarily match what is being shown in the update overlay picture. Is it supposed to match?
In content, yes, but not in geometry. The image in the Camera Control window is a live video feed that is uncorrected for distortion. The overlayed image on workspace is a distortion corrected image.
I’m guessing that the majority of the bed is likely probably in correct position but that you’re getting distortion at the extremes.
If you can mount the camera differently so that it’s more straight down and centered in the camera view you may have better luck. Also, the gap at the top of your workspace is due to not being able to see the back of the bed or because LightBurn thinks that area is inaccessible based on your alignment process.
That should likely be good enough but there is variation in the cameras from factory. You may benefit from doing your own calibration.
What test print are you referring to? Are you referring to the alignment process? Can you describe what you mean by “off”?
Sorry for not replying sooner. Went ahead and performed the connect the dots camera alignment test. Realized that the camera overlay that has seen accounts for about 3/4 of the size of the entire bed after some ex and Y adjusting the capture is reasonably close however still requires some adjustment once it is on the bed.
How large did you scale the alignment markers when you ran the alignment process? Increasing the size may get you a more accurate alignment.
How close is the overlay to actual position? You should be able to get within a millimeter or smaller at least on the least distorted parts of the image.
This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.