Camera setting with 80x40 cm laser bed

[Mushmush (Guillaume F)]

Hi dear laser lovers,

I’ve a setup made of A20 Pro with 80x40cm laser bed.

I’ve installed a USB cam to allow overlay in lightburn and it works pretty well inside the Alignment pattern (printed at 182%), but as it is a squared pattern, I have areas quite far outside this pattern envelop (say, on the 80cm Y axis, below 20cm and above 60cm).

I observed that when I print in these “outside” areas, a shift appears between the place I want it to be printed when referring to the overlay, and the place actually printed. And it seems to be proportionnal to the distance between the print and the center of the laser bed.

Any idea to solve that ?
Could we think at having an Alignement target “rectangular” in future Lightburn upgrades, to cover extended laser beds?

Thanks !

[JTR (Tyler Raps)]

If your camera has a wide aspect ration, you can orient it to take advantage of that (i.e. so the wide dimension of the camera is along the 80cm Y axis), and then enable “Rotate captures 90 degrees” in your LightBurn settings (“Edit” > “Settings”).

That will not change the alignment pattern from square to rectangular, but LightBurn should utilize your camera’s capture area better that way.

Here are some tips on the lens calibration (and alignment) process:

Tips for calibrating / aligning the camera

These are the most common reasons for difficulty with camera calibration: The camera doesn’t need to be on the machine for the lens calibration - It’s ONLY the lens and pattern that matter for this part, and the pattern can be scaled up. If you do it on the machine, if you have a honeycomb bed, cover it (bedsheet, paper, wood, etc) - the pattern gets misinterpreted as more circles and confuses the software. The printed circle pattern has to be as flat as possible . Glue it to wood or f…

And a video guide:

LightBurn Camera Lens Calibration