I am looking to purchase the best camera to mount above the 460x810mm cutting bed on the NEJE 3 Max that has the least amount of height requirement. My laser machine is in a cabinet so I am limited to height above the bed. 8mp or better. What angle would give most accurate image as I will be using it to trace scale drawings? Thanks in advance.
Cool,
Draw an isosceles triangle 850mm wide and as tall as the inside of the cabinet (minus 20mm for the camera mount). Calculate the the angle that the camera would need to have in its field of view to see the wide part of the bed.
(You can use this: Isosceles Triangle Calculator or post the inside height of the cabinet and someone here would likely do the calculation for you.)
The angle that would give you the most accurate image (requiring the least correction) is the smallest field of view angle that sees the whole bed. If you double the cabinet height and narrow the angle further you will increase your accuracy.
The wide field cameras distort the image to get the whole field on to the imaging chip. There’s some math in the lens calibration to take the ‘Fish-eye’ out and it’s pretty good but narrowing the angle will certainly help.
So if I have this right, base is 850mm, or 33.5” with the height of 16.5”, doing the calcs, when figuring for a right angle (half of the isosceles) I get 45.53* for top angle. Double that gives me 91.06* with 44.47* on each base angle. Hypotenuse is roughly 23.52”. So does this mean i need a nice 8mp 90* camera vs the 8mp 150* wide angle lens camera which works but distorts quite a bit even with the ‘corrective math’ of Lightburn?
Something like this?
Based on the triangle thing, can someone verify that a 90* lens will capture the entire bed in the field of view? Thank you in advance. Cabinet height from bed to top is 17 inches roughly. Base is the bed at 33 inches
Well got the new camera. Now lightburn keeps crashing every time I try to calibrate the lens… no matter what I do it crashes… I select usb camera, full calibration and then when I click on capture image (first black dots image in center) it “not responding” and crashes…. Kinda sucks
FYI… doing the calculations with the isosceles triangle, the viewing angles at 16” should have been 90*. This did work but i had to raise the camera to 28 inches to get the entire field of view in the frame. Not gonna work. My older camera at 150* will have to do as this will work at 16” high but there is a bit of distortion at the corners… but the middle is spot on when drawing a 1” long rectangle on a overlay image that has a ruler.
Bottom line… math is the best thing invented… but trial and error dials everything in perfect.
The laser cutter will go beneath my cnc router in the cabinet space below.
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