Cannot get good enough focus

[RedX2501 (G B)]

Hi,

We are having a hard time getting the camera to work properly.

We bought the 90° camera (unfortunately the order, #13050, does not say if it is the 8MP or 5MP and I forget) and have not had any usable results so far.

The laser bed is 800x1100mm large and the laser was mounted at ~745 mm height. The height is not as much relevant as loosing a bit of the edges of the laser area is not our main concern.

I have not yet been able to achieve good scores when setting up the camera adjustment.

I believe the problem is focusing as can be seen in the images below:

These were taken on a Win10 PC

When for testing purposes I moved the camera to about 350mm the image became clearer but as can be seen the outer parts of the text are still not in focus.

This is our setup:

And these are the scores on a Win7 PC:

What can be done to improve our situation? A camera with higher resolution? A wider field?

Thanks ahead for your support.

[LightBurn (Oz)]

The 90 degree cameras have a pretty narrow depth of focus, so they’re easier to use on smaller systems. If you focus the camera on a circle surrounding your center page, effectively averaging the focus between the middle and the edges, that will help overall with placement.

This is the chart of minimum mounting heights for all the cameras we sell, based on your machine size:

The 5mp-120 would likely be a better option for you - where are you located?

[RedX2501 (G B)]

We’re located in Stuttgart, Germany.

If 120° is a good fit, would the 8mp N 120° be even better? We might just order that then and use this camera on our smaller laser (900x600mm).

[LightBurn (Oz)]

It really depends on your mounting height, and the two 120 degree lenses don’t see the same amount of bed area because of the way the lenses are mounted:

The 8mp-N-120 has a wider viewing angle, so it doesn’t need to be mounted as high. If you mount it where you have the current one, you’ll see extra area around the bed, but that shouldn’t be a big deal.

[RedX2501 (G B)]

I’m a little bit afraid of ordering the 5MP 120° just to discover that the problem is on our side.

Do you believe that using the the 5MP 120° should give clear results across the laser bed? Unlike our current pictures?

Are there any alternatives (maybe on Amazon) that would ship faster? Last time we ended up waiting 30 days for the journey over the great sea.

[LightBurn (Oz)]

The lenses used in the 5mp cameras use an M8-size thread. You should be able to find other lenses with that same thread size on AliExpress and possibly other sites as well, allowing you to try a couple different options. In theory, just about any available USB webcam should work with LightBurn, but in practice there are still some compatibility issues with some that we’re trying to pin down. If you’re using the ‘Custom’ capture option in the settings, you’re probably ok to try a couple other options. Spinel and ELP cameras from Amazon have tested well for me.

[RedX2501 (G B)]

In your opinion the resolution of the camera should be plenty for the bed size then. It is purely a lens problem here?

[LightBurn (Oz)]

1100mm is a big bed, but the camera captures a 2592 x 1944 image, meaning you should get about 2 capture pixels for each mm of bed area in X and Y, giving you about 1mm of theoretical maximum accuracy. If that’s enough, then it’s a lens problem. The 8mp-N camera captures 3264 pixels across, so you’ll increase the possible accuracy a little, but the difference won’t be huge.

[RedX2501 (G B)]

In the last images the camera was considerably closer to the laser bed and yet the calibration values were still bad. What can be the cause there? I mean if even at closer distances I can’t get the lens calibration done I’m unsure if any other camera would help.

[LightBurn (Oz)]

The sides were still pretty blurry in that image, and that would play a big part. It also looks like you just had the pattern on paper, and it was wrinkled, not glued to something flat. That will mess things up a lot - the software knows what the pattern is supposed to look like, so any difference between the theoretically perfect version and what the camera sees is assumed to be lens distortion.

[RedX2501 (G B)]

If at 30cm the blurry sides still affect the score that much how do people get the 90° camera to work?

I’ll definitely try glueing the paper on a piece of wood and see if I can calibrate it to focus better on the edge.

[LightBurn (Oz)]

@RedX2501

If at 30cm the blurry sides still affect the score that much how do people get the 90° camera to work?

I suspect the blur isn’t the issue in your case. I’ve been able to get successful calibrations with scores < 0.2 with every type of camera we sell.

[RedX2501 (G B)]

So after completing the lens adjustment barely, all scores were 0.5 and higher, up to 0.8. I tried doing the calibration and i could see the points ok-ish.

Then trying to laser was disappointing.

With the same camera i could barely see markings i made on a piece of wood.

With a different board behind to reduce the contrast it was better and i tried lasering with an offset the marks.

The one in the middle was fine but the one in the border is very off. See both images below.

What can i do about it?

[LightBurn (Oz)]

Did you raise or lower the height of the bed after you did the capture? That would cause the alignment on the sides to be off.

[RedX2501 (G B)]

So after buying a camera from ELP all my problems are gone. The whole bed is focused and the calibration and alignment went smoothly. The new camera is 100° and 13 MP.

The offset is now only present in the y-axis which indicates a non stable setup (which it is and will be fixed soon).

I’m pretty sure the lightburn camera has some quirks but I’ll try it out on the smaller bed just to confirm soon.

[Audrey (Audrey Watt)]

Hi Red

I’m having the same issues. Did you get your LB camera to work at all?

Thanks
Audrey

[LightBurn (Oz)]

This thread has 15 previous posts in it - can you elaborate on which “same issues” you are having? Did you also get the 90 degree camera?