DIY Laser levelling using webcam and laser level

[devmonkey]

Hi Devmonkey

A logitech webcam was also tried it worked but there were strange fresnel like circles produced with the laser. The logitech camera had a quite large lens. The laptop camera did not display the same aberrations. its camera is tiny.

I also tried a fuzzy pencil line drawn on paper that worked OK too.
A piece of wire should be no problem.

If you are using a laser with the (crap) optics of a webcam then you will get all sorts of weird patterns and probably more problematic non-linearity meaning each pixel will register slightly different height errors, best to get an old or cheap webcam and rip the sensor out and bin the optics. If you want to stick with optics then use a piece of white paper as a screen between the laser and the camera, focus the camera on the screen.

With the pencil line did the gaussian detection work? I would be surprised if it did as the pencil line would be lower intensity than the paper. I would need to invert the intensity I would think for this to work properly with a pencil line or wire. Also to use as a shadow camera you will need to flood the background with an even light source, maybe a white led behind a piece of diffusion perspex (the translucent white stuff). This is to eliminate false triggering from the otherwise random background intensity of your workshop wherever the camera is pointing.