Camera flipped overlay bug?

I’ve installed the Lightburn camera, but I’m having a peculiar issue where the camera control preview shows correctly, but when applying the overylay, the image mirrors horizontally. Is this a bug? I can’t seem to find an option to flip it.

Also, is there a way I can get a larger area of the bed to show on the overlay? The preview shows far more than what is displayed in the overlay.

When you tagged the markers, did you do them in numeric order? (1, 2, 3, 4?) I’ve seen this happen if they’re tagged out of order, but I don’t think I’ve seen it flip like that otherwise.

Regarding the scale, I’m working on a fix for this. It’ll mean redoing the alignment marking, but you won’t have to do the lens calibration again.

That was the problem exactly! Thank you

I have the base k40 with C3d control board . did the same, picked the 4 targets out of order and got strange results, then read the instructions. Worked much better,
BUT, I am still not entirely happy with my camera. As I had a spare chassis (burnt out hulk from last Summer’s fire) I took the opportunity to salvage the lid, cut the opening to be symmetrical over the cutting area & repaint it. My camera is a 170 degree, and as there is no plexiglass window (FIRE) I mounted the camera above the center of the cut area looking straight down. It is about 1 1/2 inches above the surface of the lid. A plexi dome to be above the camera is being fabbed.
Here’s the thing, when capturing images for alignment & calibration, I was not pleased with the scores, .75 or thereabouts. The example shows the camera looking at the table at an angle, and the dot pattern held at an angle. My camera is looking straight down.
Any suggestions for improving my capture scores and a better final image.

I did a walk through video for the calibration and alignment, and that talks about a number of things you mention (card angle relative to the camera, best camera placement, etc).

A couple other things to check:

  • Camera is in focus
  • Lighting is relatively consistent (lots of these have auto-exposure)
  • Calibration card is very flat
  • Capture is at high resolution, not 640 x 480

A 170 degree camera is going to be harder to calibrate, particularly at the edges of the image. If you have to bring the card inward, away from the edge of the image to get a good capture, do so. The code is measuring the curvature of the lens, and with extreme fisheye, there’s so much distortion at the edges that it can be hard for the code to find the dot pattern. The lens curvature is consistent across the lens, so it’s OK to move in a bit.

Thanks for the quick response. I will redo it tomorrow. When I printed the dot pattern, it printed it much larger, I used it as just a sheet of paper. Will reprint at proper size and glue it to a board and go thru the steps again.
Thanks again.

The size is less of an issue - the important part is that it takes up roughly the correct portion of the camera view, and that it is very flat.

I reprinted the circles at proper scale (my printer had been set at 200% ). glued it to a board for flatness, got anywhere from .3 to .6 on scores, YAY!
Finally, is there a way to check resolution or settings or focus (assume fixed focus on most plain cameras)
Thanks again.

LightBurn displays the camera resolution for you when you do a calibration capture:

For focus, the easy way would be to un-dock the Camera Control window on the main page and drag the window larger to expand the camera view. One of the other members shared a trick he used that worked well here: Simple Aid For Focusing The Camera

Ok, I get that, but, how do you change resolution?

You don’t, at least not on Windows for the time being. The framework LightBurn is built on is how it accesses USB cameras, and the Windows version doesn’t allow setting the capture resolution, so you’re stuck with whatever the camera defaults to.

This is why we started selling cameras - most webcams default to 640x480, some will default to 1920x1080. I got the company that makes them to set the default to the highest res instead of the lowest until I have time to rewrite all the capture code.

Thanks. Just having a hard time with a component capable of different resolutions but no way to choose. like a car with a 6 speed transmission and no way to shift gears.
Oh well, may have to break down & buy another camera (LB).