Camera alignment issue right after calibration

[sam240 (Sam)]

Right after I finish alignment, I run a small test and the position of the laser is off a little. I’m using a 8mp camera. I tried alignment scale 190 and 180 and 150 and nothing seems to be helping. Each result is off. Camera is not fixed to the door, I have it fixed in place and it doesn’t move. I have the latest version of lightburn. I’m using Creality Falcon2 22W laser. Any help is appreciated.

[berainlb (PY)]

Can’t tell from the screenshot the scale of the misalignment. What are the units you are using for display?

If you’re within a couple of millimeters of alignment and repeated camera alignment doesn’t get you any better then you may be able to use the width/height and XY Shift fields in fine tune the alignment:

1. create a uniform grid of squares across the entire workspace in LightBurn
2. burn entire design onto material and leave in place
3. capture overlay
4. use width/height and XY Shift fields to as closely align all the squares on the grid. It’s possible with distortion that you may not be able to get all squares to align perfectly so try to get to a best compromise situation.
5. Right-click in Camera Control Window and make sure to save the calibration or else you’ll lose the adjustments.

If after that you can’t get to acceptable results you may need to restart with lens calibration and camera alignement. Make sure you’re getting the absolute best scores in the lens calibration as you can.

[sam240 (Sam)]

Thank you. I will try that.
Do you know what could cause the alignment not to match? is it the camera? I was using inches in the screenshot.

[berainlb (PY)]

It’s a combination of factors including but not limited to:

1. the lens calibration is suboptimal for your camera
2. inaccuracies during the camera alignment process
3. something that’s changed from the time the alignment was done and actual work time. For example, in reality the alignment is only accurate with a single given thickness of material or rather distance to lens from material

In practice, cumulative errors built-up along the entire dependency chain contribute to things being off. Not sure what your expected tolerance levels are but with very good tuning you may get to sub-millimeter precision. In practice, precision to 1-2 mm is fairly reasonable.