hi i have some questions.

im building an LLP installation, and when i test it in the chairs the blobs are detected perfect, then i make in the desk i build but the blobs now are invisible, now they are not detected.
what do you think is going wrong ??..

i have the ps3 camera with a filter i extrat from a floppy.
maybe the distance between the camera and the acrylic ??
can someone give me some direction to solve this problem ??

thanks…

I think the problem is your projecting surface. It might be that it doesn’t let IR go to the webcam.
Try it again on your frame, but without the white projecting surface.

i have just try without that white paper, but what i see is the projection…

? what do you mean? try it without turning the projector on. The best option is always getting a proper filter for your cam.

ok, thanks.
which is the best filter you can recommend me ??…
and another question, what happen if, without the projector on and without the white paper we cant get the blobs ??
is this a problem with the lasers ?? with the distance of the camra ??, because if i test this with the camera closer to the screen i can get the blobs perfect.

thanks.

I bought this filter (note: I’m using 780nm 25mW laser from aixiz)

http://cgi.ebay.com/NIR-Optical-Filter-780DF60-25mm-dia-w-metal-ring_W0QQitemZ310131624246QQcmdZViewItemQQptZCamera_Filters?hash=item4835490936&_trksid=p4634.c0.m14.l1262&_trkparms=|301:1|293:1|294:30

it works perfect for me.

And your other problem: yes, the problem is the distance from the camera to the screen.
Could you post some info about your lasers?

I’ve said this in the past in other posts as well, but I cannot stress the utmost importance of proper laser alignment - scotch tape is not going to hold your lasers in proper alignment for more than a moment

the size of the acrylic is: 24 * 18 in.
lasers: 780nm 10mW
camera ps3, without ir filter and with a floppy filter
projector epson emp-62, Image Brightness 2000 ANSI lumens

this is what i have.

which is the best projection surface you recommend me ??

have you also calibrated your lasers so they are right above your surface?

I think he did, cause he gets blobs when the camera is close enough…

-You could try vellum as projection surface
-Then it again in a dark room without the floppy filter in your ps3 (best option, buy a proper filter)
-Try hot glue for holding the lasers.

any time i’ve used a floppy as a filter it ends up bad.

OLD FILM WORKS AMAZING.  2 pieces of old film. dig through your collection and find the old ones where at the end of the roll they leave about an inch of black film.

but to see if that’s the issue, just go without the filter and see if that changes anything (turn off all sources of visible light first though)

Yesterday i try with an old film, but just one piece and doesnt work for me, maybe two can change things
yesterday i ordered the filter you recommend me too
if i power off the projector i think everything is ok
i secure the lasers, in one moment i post a picture you can see how i secure them, i think they are calibrated, well that what i try, but how can i can be sure
that they are calibrated right??

About vellum, how can i vet one of that here in mexico?? Do you know the name in spanish??
Thanks a lot

How do you know if the lasers are calibrated enough? --> see this video: http://vimeo.com/3019646?pg=embed&sec=

you could replace vellum with a very thin sketch paper. note: it schould be very thin.

i found a vellum paper.
INK JET VELLUM PAPER FOR PLOTTER

do you think this paper can help me ??…

in the pictures i attach you can see how i mount the lasers.

i see the video of the calibration of the lasers, and i have one question the light the is meitted by the laser need to be thin ?? focused ??, but at hwat disttance i need to focus the light ??

thanks for all your help.

You could try it, as longs it’s thin to let the IR light go through it…

The thinner the light of the laser is, the better. But, there’s no problem if you’ve thick laser lines…

see this image, you might understand what I mean

ok, thanks....

just an stupid question but i need to do it for next projects.

can i use lasers of different types, for example different nm or mW ??
i imagine that its not recommendable to do this.