Projecting an SLS system: Scanning precision

Write here about construction, ideas, equipment, tips n tricks etc. related to structured light scanning
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Micr0
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Re: Projecting an SLS system: Scanning precision

Post by Micr0 »

mading wrote: 16 Mar 2017, 09:46 Well, let's say I can't put anything.. I'm sorry but it's too risky.
Has anybody tryied a DIY IR laser setup?
Or IR LED DLP Projector?
I understand. The cost of a mistake on a very valuable vintage instrument is way to high. As for the Infrared idea. the problem isn't the infrared Laser, it would be the camera. Most visible light cameras actually have infrared filters on them. The exception to this are cameras for astronomy or cameras specifically designed for infrared. However, here I have no experience.
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VDX
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Re: Projecting an SLS system: Scanning precision

Post by VDX »

... digital cameras are much more sensitive to blue, than to red or IR (and blue gives finer lines/patterns too) - so better think about a green or blue line-laser or a modified DLP-beamer with a 445nm-blue- or 405nm-UV- laserdiode instead of the original lamp (if the normal blue setting won't be enough).

Viktor
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mading
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Re: Projecting an SLS system: Scanning precision

Post by mading »

Thanks to all.
Victor, I do not understand the advantage of using a blue led source on a dlp beamer.
I heard that red-IR light performs better on dark, translucent surfaces affected by polarized reflection.
As wooden musical instruments.
So theorethically we should move to longer wavelength.
And shop for an IR industrial camera..

Did anibody used polarized filters on source-camera?
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
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VDX
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Re: Projecting an SLS system: Scanning precision

Post by VDX »

... I've mentioned replacing the original lamp at DLP-beamers, because I did this several times for UV-3D-printing with 9W@405nm-LED's and in the testing phase with 405nm and 445nm laserdiodes too.

Don't know exactly, but the 405nm/445nm wavelengths should be much sensitiver for common camera chips ...

Viktor
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mading
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Re: Projecting an SLS system: Scanning precision

Post by mading »

Hi ViKtor.
my question was a little bit crude, sorry!
I gave a better reading of your post: I understood that camera performs better with lower wavelength, but apparently my violins should work better with longer ones.

Thanks again to all for your precious support.
I'm going to start from the basic setup: ACER k132-135, dmk 23ux236+12mm 1.2 Cosmicar-Pentax.
If somebody has a suggestion for red-IR line laser, I'll probably give a chance also to laser scanning.

Best wishes to all!
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
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VDX
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Re: Projecting an SLS system: Scanning precision

Post by VDX »

... I'm working with IR-laserdiodes with 808nm and 975nm too for laserengraving - the "normal" digital camera (with IR-filter in place) will see the (for human eye invisible) spot or laserline as a "pinkish", poorly defined light - but too, much weaker, than it should be (could be the IR-filter).

A "blue" laser-line is much brighter, finer and sharper than the IR-laserline ... and the 405nm could be even better in respect of contrast and reflectivity/visibility on white, black and specular/reflective surfaces.

So my suggestion is - better search a 405nm-laser (found in BluRay-players) for better and easier to achieve results ...

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avogra
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Re: Projecting an SLS system: Scanning precision

Post by avogra »

mading wrote: 17 Mar 2017, 08:06 Thanks again to all for your precious support.
I'm going to start from the basic setup: ACER k132-135, dmk 23ux236+12mm 1.2 Cosmicar-Pentax.
If somebody has a suggestion for red-IR line laser, I'll probably give a chance also to laser scanning.

Best wishes to all!
I would rather go for a 10mm lens. I use your suggested setup and if camera and projector are mounted to the same rail, the camera image is too small.
mading
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Re: Projecting an SLS system: Scanning precision

Post by mading »

Thanks Avogra.
Unfortunately the lens is the only component I found used.. :lol:
Will keep searching ebay auction for the projector!
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
mading
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Joined: 31 Jan 2017, 13:09

Re: Projecting an SLS system: Scanning precision

Post by mading »

Hi to All.
I'm impressed about all the contribution that you can find in this and the old forum.
Thanks guys!

BTW my K132 and DMK 23UX236 are coming!

I made my own calibration panels with scrape parts (19 mm particleboard) and printing on photographic paper with ink-jet. Not the best precision but I hope a decent start.
I was fascinated by the post on SONY laser source projector, but I decided to start from a classic.

cheers!
LG PF50, LG PF1500, RangeVision DIY: 2x DahengMer630, 2X12 and 2X16 mm 5Mp ZK lenses, RV turntable
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Micr0
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Re: Projecting an SLS system: Scanning precision

Post by Micr0 »

mading wrote: 20 Apr 2017, 12:25 Hi to All.
I'm impressed about all the contribution that you can find in this and the old forum.
Thanks guys!

BTW my K132 and DMK 23UX236 are coming!

I made my own calibration panels with scrape parts (19 mm particleboard) and printing on photographic paper with ink-jet. Not the best precision but I hope a decent start.
I was fascinated by the post on SONY laser source projector, but I decided to start from a classic.

cheers!
The inkjet printed calibration panels will be plenty precise to start with. You will have more deviation in just assembling the left and right panel....

Let us know how it works out.
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