Re: Laser Scanner
Bjørn, Sat Aug 12 2006, 05:23PM

You could try to make a scanning dot camera like some of the first TV cameras. You could get pretty good resolution, infinite depth of field and a very slow framerate. It would only work in the dark, but could be quite interesting.

You could record the reflected brightness as a sound and get someone else to make the software that turns it into a picture if find that kind of thing boring.

Re: Laser Scanner
Tesladownunder, Sat Aug 12 2006, 05:34PM

I mainly built it to use at a demo I am giving next week. I will run it at knee level. TV will have to wait.

Here is a hand picture. It is not a double exposure. Note how the hand is "not there" and you can see the carpet through it.

Peter

Re: Laser Scanner
Carbon_Rod, Sat Aug 12 2006, 08:40PM

What you may want to try is grabbing a new mirror and optics. That aluminium mirror comes from old laser printers (not LED based, under 600dpi, and usually located above the toner cartridge). Local repair shops would likely have junked modules with only fried laser diodes. Or buy an old printer for $20.

Some old in-counter laser checkout stands (I think 1980’s) had a 10” spinning partitioned holographic disc. If you can find one – they can make all kinds of interesting scanning assemblies.

Cheers,

Re: Laser Scanner
Madgyver, Sat Aug 12 2006, 09:33PM

As i Understand you, you were projecting an image of your Hand on the Carpet right?

How do you put in the "Data" of that image and how do you make the Y-Axis translation? With a galvo?

Pics please =D

EDIT:
Ah damn. I just read "not double exposed" and understood "not long time exposed".
Sorry for my lame-assness. I am a bit tired from learning for Pre-Diploma exams.

Re: Laser Scanner
Electroholic, Sat Aug 12 2006, 10:06PM

Interesting, is it like a POV effect or something?

Re: Laser Scanner
..., Sat Aug 12 2006, 10:06PM

TDO just put his hand in front of the scanning beam with a mildly long exposure(me guesses about 1s) and moved it through the beam. Each pass scanned in a slightly diferent spot giving the neat looking 3d floating hand. You can see though it because his hand was not in front of the camera the whole time, so some light from the carpet got to the camera.

Very neat!

Now that you have a laser canner you need to take it out ay night sometime and let out some smoke... It is realy cool with just hand scanning the beam at a few hz, I wonder what it is like with a barcode scanner...

Re: Laser Scanner
Steve Conner, Sat Aug 12 2006, 10:34PM

I'm puzzled how you managed to take that picture TDU. The hand is pin-sharp, so it can't have moved relative to the camera. And I can see the camera didn't move relative to the carpet either. Also, I know those scanners only make a line, not a 2-D raster like in your picture. Did you open the camera shutter, then put your hand in front of the lens and move the scanning unit to swipe the beam over it?

I'd love to see you make a flying spot camera a la John Logie Baird.

Re: Laser Scanner
Tesladownunder, Sun Aug 13 2006, 12:52AM

Exactly right and the exposure was 1 second. If you move your hand up towards the camera then it will be scanned. Once it is out of scan range, remove it so the camera continues to expose on the carpet. You will have minimum distortion if the hand moves towards the camera.

I have 2 laser printers to scrap when I get the time. I also just picked up 2 argon lasers (free) used in big image scanners. Lots of optics and power stuff. The lasers work but power is down from 40mW to 8 and 20mW respectively.

I did some smoke pics. While they were good to look at, the pics weren't that good, then my smoke generator died, so another day.

Here is a couple more shots. I have some really cool room shots next. My wife said "WOW!" when she saw them so obviously appealed to her redecorating nature.

Peter

Re: Laser Scanner
Tesladownunder, Wed Aug 16 2006, 12:32AM

Well, 48h and new information...
Here are the room scans, made by sweeping the room in both direction.

Peter