Camera suggestion besides the LightBurn one?


(Dan Suskin) #1

I have the LightBurn camera, and its ok, but the focus is very, very finicky (with essentially no depth of field at all), an d the image is not great when zoomed.

Anyone have any suggestions for a better camera I can use?

Thx


(Blake Bartlett) #2

Have you adjusted the lens to sharpen focus?


(Dan Suskin) #3

Yes. And that’s the issue. It is very finicky. On a wide view it’s all good but zooming in for precise placement yields a very poor, pixelated image.

And with it being a flat field lens it has little depth of field so you have to refocus for every material thickness even if it’s only marginally different.


(Dave Jones) #4

Camera has been a sore spot for me too. As much as I love the Lightburn software and I inversly dislike the camera for its poor picture quality, erratic focus, and wonky calibration issues.


(Oz) #5

“…you have to refocus for every material thickness” - If you set the focus height of your Z to the same point this isn’t an issue. If you’re not doing that, you’d need to redo the camera alignment process as well.

Your profile says you have an HP3655, which means a 1400 x 900 mm bed. The LightBurn camera, at 2600 x 1950, would be able to resolve details down to about 1/2mm with that size of bed, at best. Can you show an example of the image you’re getting?


(Dan Suskin) #6

“If you set the focus height of your Z to the same point this isn’t an issue. If you’re not doing that, you’d need to redo the camera alignment process as well.”

Well, there’s a thought. This is not mentioned in the calibration or setup instructions. I’d suggest adding that as it clearly would help the issue. I should have thought of that myself.

However, the problem is not just having to refocus (probably that won’t be an issue given the above) - but in order to precisely place things, you need to zoom in a lot from such a wide view camera - and that results in a very pixelated image that is not very useful. At those magnifications, you simply cannot get a clear enough image to make precise placement possible.


(Dan Suskin) #7

Actually, the more I think about it, using the Z focus height will not resolve the issue. With both the laser head and the table being able to move, the distance from the bed to the camera will not be consistent even when the Z has been correctly set - only the distance between the laser lens and the material will be consistent.


(Isaac Barbary) #8

The distance from the camera to the in focus plane does not change. Lowering the bed to fit thicker material doesn’t change the depth the laser is focused at and that is where the camera needs to be accurate. Set the bed height to the laser focus height while setting up the camera.


(Oz) #9

Unless you’re swapping out different focal length lenses this isn’t true. The distance from the bed to the camera is irrelevant. As Isaac mentions, the distance from the top of the material to the camera is the important bit.

When you say, “from such a wide view camera” - The camera view is generally chosen to match the area of your machine, to fit the bed area as closely as possible. How tight are you zooming in to line up things? If you don’t need to use the whole area of the machine, you could move the camera closer to the bed and use a cropped area in the center of the bed - that would give you higher precision, but you wouldn’t be able to use the camera for the whole bed.

I’m working with our camera supplier to try some of their other offerings, including higher resolution cameras (8MP) which would help in your case.


(Dan Suskin) #10

No - Isaac and you are both incorrect. That would only be true IF the laser head was always in the same place - but the laser head moves AND the bed moves in order to bring the material to the focus plane. The BOSS autofocus moves the laser head to achieve focus - so if the bed/material is lower than previously, the head moves lower to achieve proper focus (and vice versa). There is NO way to put the bed/material at the same distance from the camera every time without a very manual method of measurement each and every time.


(Oz) #11

This is something that I didn’t know - that said, the critical part is the distance from the top of the material to the camera. If you can keep that distance the same, you should be ok.


(Dan Suskin) #12

Exactly. And as I said above, that would be almost impossible to do. To get it correct to within the very limited depth of field the camera has would be extremely time consuming and likely not even possible.

The answer clearly is a more capable camera, and one which either has autofocus and/or a vari focal lens.

Let us also remember that because the distance to the material is NOT consistent, the camera calibration is not accurate anyway.


(Isaac Barbary) #13

I haven’t encountered this before. All of the lasers I’ve seen or used have fixed heads, including Epilog. You’re going to have to go with a camera that can handle autofocusing then. I don’t know what else to tell you. A webcam just isn’t equipped to deal with this scenario.


(Isaac Barbary) #15

It moves the laser head up or down? Are you sure about that? I looked around the Boss website and I didn’t find a single laser with such a laser head. Got a link? I would like to learn more about it.


(Dan Suskin) #16

I am absolutely sure. But to be clearer, here is the autofocus procedure:

The user manually jogs the head down to the low limit switch, or as close as you can to it. Then, when you press the autofocus key, the bed/material moves up to touch the laser head - which itself is then pushed up again until it triggers there autofocus switch , and then the bed moves down to the predefined focus distance and the laser head return to the place you arbitrarily moved it to.

So, you initially move the laser head down to a position close to the limit switch - BUT there is no way to move it to exactly the same spot every time


(Dan Suskin) #17

Well, there might be a way to manually move the laser heads to the same spot each time before using the autofocus procedure … I’ll check that out later and get back here


(Blake Bartlett) #18

So no link or more info on the laser head?


(Oz) #19

Look at the head in the 3rd and other images on this page.


(Blake Bartlett) #20

Interesting. Wouldn’t that throw off beam focus? I suppose that’s the point? Would that allow you to cut sharp, and also engrave unfocused for a darker, but shallower burn?


(Oz) #21

For metal cutting you often do “live focus” where you refocus often during the cuts because the focus point needs to be very precise, partially because of very shallow depth of focus, and because metal sometimes distorts during cutting because of heat.

I’m not surprised to see the live focus, I just didn’t realize that the Boss laser system used movement on both the bed and the laser head to do this.