About ⅓rd of the size of the camera’s viewing area in both directions (1/9th of the its entire field of view), when viewed through the camera
so does this mean the Calibration-Circles sheet has to be equivalent of 3 sheets on top and 3 side 3X3 (Pic 2 and 3 below), so total of 9 sheets should fit in the camera view Area, but what about Wide (‘W’) angle camera (pic 3 below), this might not work for wider side of the Camera view area (pic 3 below)? Let me know if my assumptions is wrong?
Regarding the margin, yes, like your image, you need a bit of whitespace around the whole image, the gap between the circles is not as important, just keep it as per the file provided.
You want it like camera view N, roughly, it’s not exact. But you will only want one area filled at a time, so you only need to print 1 copy, and stick it to something very flat. This is very important - glass from a picture frame is a good option.
Your image appears stretched vertically in these views, do not change the aspect ratio of the image (do not distort it) before printing it. The unstretched image will fill a wide angle view better.
i still have to build an enclosure that is why i am trying to figure this out first, but i do have a wide 95degree camera that i am testing with at the moment before i build an enclosure
but was just wondering the extra area for a Wide angle camera (in red in pic) would cause any issue and the green is the machine?
since the calibration sheet would not be used in that area i assume
or if that extra area with the Wide angle camera would mean i would get bad calibration?
So, the above “calibrate camera lens” step is what i am a bit confused about, i have a Wide angle camera that is picking up area that is outside of the machine areal (it picks up empty table space, not used for any thing, useless space), so that is why i am wondering if the extra space (Red in pic below) that shows up is an issue, when using the calib sheet with the dots. Since the sheet would not be put in the extra empty useless table space for the calibrate camera lens?
You need a camera, you don’t need the camera to be in the machine, nor facing the bed.
You want to use the dots (again, not stretched -they’re still stretched in your image) on the edges of the camera view, not the bed.
You can calibrate your camera outside the enclosure, then install the camera in the enclosure and align it within the enclosure. You can save the calibration file for future, just to be safe, so you don’t need to remove the camera again if you ever lose your settings or anything strange.
Failing that you can still try to calibrate it within the enclosure, the field of view will still be there, it doesn’t get cropped by the enclosure, the camera just sees different stuff (like the inside walls of the enclosure) within the same field of view. You can, for example, prop the dot card up at an angle on the edges to get it to fill the view.
But given that you have the camera now, and are testing it, I would calibrate it now.
You can calibrate your camera outside the enclosure, then install the camera in the enclosure and align it within the enclosure.
interesting so does this mean the camera can be at almost any height, to do calib or it has to be the height that is appropriate for cut/engrave area size
I am a different new user but the thread is relevant. I have the current LB version and the AlgoLaser Delta with the current software post. I just purchased the fixed-focus lens and camera support from AlgoLaser. No matter what I have tried I do not get the pattern recognized. Is there anything else I can try other than what is in the documents?
i had gone over some it but herd that people were finding way to get better results through other means as well so was inquiring about detail that i might have missed or were not included in the doc
I don’t know if this will help but this might help you confirm certain things about your camera/calibration I have not fully tried this my self but plan on in the near future
You can try using some old cell phone you might have laying around as cam or even your current phone as a cam for light burn
You can download app on your phone/s that turn your phone into a webcam especially since phones this days have much higher mega pixels, this can be a extra bonus also has the added benefit of giving you a wireless cam as well ( if you do a bridge type setup with Raspberry Pi and connect the cam to it the whole setup machine/cam/etc… can be made wireless……but for the future)
Look for apps that support 4k or more you prob could use lower then 4k as well its just a personal preference
once you have your app picked out and working on phone/Lightburn you can further improve accuracy by downloading a Protector app that can help you get near perfectly align your camara/phone straight and flat in X/Y rotational directions (assuming your bed is also straight/flat), and mount and attach to top of machine, I use this one for woodworking purposes
I would like to understand how it is not necessary to have the camera on the machine to calibrate it .
I must be missing something fundamental in my understanding .
Please explain how this is so , thanks .
The point of lens calibration is to examine the image of a know pattern and remove any distortion of the pattern. The distortion may be inherent (a fish eye lens is distorted as you move out from underneath the camera) or unique to the camera (manufacturing difference from optically perfect, defect in the chip, etc.). Most cameras will have both.
The calibration process uses a know image (the circles) so that the software can adjust what it sees to match what it knows the pattern should look like.
Since the process has nothing to do with the position of elements in the machine you can get calibration of a camera outside of the machine. I expect that the camera elevation should match the eventual installation height since the distance from the camera to the object will impact focus and distortion.
I got this from the documentation although I had the same question to start.
The calibration only deals with the warp of the lense, it gives LightBurn the info it needs to be able to ‘unwrap’ the image appropriately so it can lay it flat.
The alignment is the part that actually relates that flat image to the placement of the bed and machine.
