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How do you do this? Laser drawing on a building from far away

Rubycon

Madame President
Aug 10, 2005
17,770
482
126
The image you see on the building is *not* the laser. The laser pointer was used to "draw" the image and a camera hooked to a pc follows it and has a projector draw the image. So wherever the laser is pointed, a "painted" afterimage will appear.

The source code was posted a while ago. All it requires is a webcam on a USB port and a reasonably powerful (>2000 lumen) projector. I believe the PJ used in the video was around 5000 ANSI lumens. Smaller PJ's obviously won't be as bright on a building far away but still can work.

Even without a PJ, this would work on a regular TV/computer screen. The laser pointer has to be bright enough for the camera to pick up. A 5mW pointer is fine for indoors. In the video they were using a 50mW pointer which is NOT eyesafe at all - and at the end the "stunt" pulled was quite foolish. Not recommended that ANYONE do that unless you're trying out for Jackass 3. :laugh:
 

TheGizmo

Diamond Member
Dec 31, 2000
3,627
0
71
Originally posted by: Rubycon
The image you see on the building is *not* the laser. The laser pointer was used to "draw" the image and a camera hooked to a pc follows it and has a projector draw the image. So wherever the laser is pointed, a "painted" afterimage will appear.

The source code was posted a while ago. All it requires is a webcam on a USB port and a reasonably powerful (>2000 lumen) projector. I believe the PJ used in the video was around 5000 ANSI lumens. Smaller PJ's obviously won't be as bright on a building far away but still can work.

Even without a PJ, this would work on a regular TV/computer screen. The laser pointer has to be bright enough for the camera to pick up. A 5mW pointer is fine for indoors. In the video they were using a 50mW pointer which is NOT eyesafe at all - and at the end the "stunt" pulled was quite foolish. Not recommended that ANYONE do that unless you're trying out for Jackass 3. :laugh:
haha yea, that part at the end had me cringing.. i bet that would do some permanent eye damage. can you reccomend me a laser pointer? i have a 2600 lumen projector i'd like to try this on the side of my house with my laptop, i got a webcam too. seems all i need is a powerful laser pointer
 

Rubycon

Madame President
Aug 10, 2005
17,770
482
126
Originally posted by: TheGizmo


haha yea, that part at the end had me cringing.. i bet that would do some permanent eye damage. can you reccomend me a laser pointer? i have a 2600 lumen projector i'd like to try this on the side of my house with my laptop, i got a webcam too. seems all i need is a powerful laser pointer
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