Trying to wrap my head around how the camera is used with a Z-Axis that moves and a stationary bed that never moves and how camera alignment works.
I have done the lens and alignment procedures and everything looks good.
It seems that most of the information and forum threads are about Chinese C02 type lasers and using cameras.
So my question is, if I do the camera setup using the bed of my machine and then due to the fact that I work wither materials that are many different thicknesses, that the camera captured image will always be incorrect.
A real example that I tested was using a pencil laid on the bed and then I clicked capture, now the pencil surface I am going to burn on is roughly 7mm high from the bed (camera calibrated here), I do a capture and I can see the pencil fine, I zoom in on the pencil and place some text on it. When I run the FRAME on it, its off by about 2mm in each direction.
Another example, I do all the calibration and setup to my bed. Then I put a material on that is 100x100mm square but it is sitting inside a jig that raises the material 40mm off the bed, is the camera capture going to be inaccurate. Is it true to say that you basically would have to have an individual calibration for all the possible material heights you may use?
It’s much harder to use the camera with a variable height laser head. It’s possible, but kind of annoying.
The camera alignment is valid only for the exact distance from the alignment card to the camera. If that distance changes, the alignment will be off, and how much will depend on the lens angle of the camera, the mounting angle, and how different the height is from the aligned height. If you’re using a top-down view with a narrow angle lens, the difference will be much less than if your camera is wide angle, or viewing from an angle.
You can do alignment for a given height by engraving the alignment marks at that height. Right-click in the camera control window and save that alignment information. Then, do another at a different height, and save that one too. If you name them for the heights they were done at, you can import camera settings for the closest height to whatever you’re engraving. If you have a 160 degree lens, you might need to do this for 1/8", 1/4", etc. A narrower lens might get away with spacing them apart more.
I’m curious if there might ever be a drop down on camera control to select from multiple calibrations. I have several lens holders preloaded with different focal lengths (each one then lending itself to different heights in Z).
It’s not a show stopper. If I need to use the camera, I just use an autofocus block to position the bed on that one calibrated level, capture what I need or place objects as I need, and focus appropriately for the lens I have installed.
Thanks for clearing that up for me. My camera is a 120 degree. So you dont have to do the lens calibration again, just burn the new alignment marks for each height I need and save them.