Laser Projectors and Scanning (LG HF80LA)

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Micr0
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Laser Projectors and Scanning (LG HF80LA)

Post by Micr0 » 31 Jan 2020, 03:26

Today i got to play around with the new(er) LG HF80 projector. The light source is not LED but Laser-phosphor wheel. It's a 1080p projector but the image is incredibly sharp, and the colors are very vivid. I was not able to take it to my shop and try it for scanning but will hopefully get my hands on one in about a week or so. I checked and this projector still uses a DLP mirror array but like other LG projectors has the square pixels, and the window screen seems very fine. About 3 years ago I tried using a small pico laser projector made by Casio and it was terrible for 3d scanning. I didn't have very long to experiment with it, but the scanned surfaces were extremely rough. I assumed it was due to the highly polarized light that give laser spots a perceived twinkle when you look at then projected on wall. The image from this HF80 also had a bit of that but it wasn't nearly as bad as I remember the Casio being. I don't know much about laser light and how a camera CCD or CMOS would be effected by it. If anybody here has thoughts on this I'd like to hear them.
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OBNRacerMan
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Re: Laser Projectors and Scanning (LG HF80LA)

Post by OBNRacerMan » 31 Jan 2020, 06:47

I can’t say anything significant about polarization (maybe it depends on the type of laser - because David Laserscanner saw laser pointers both red and green perfectly).
But I am much more confused by the moment of projection distance - those laser projectors that I saw are installed almost close to the screen (and, at the same time, they had a huge projection area.) - but this is definitely not suitable for scanning.
My projector also has a similar drawback - a too wide projection angle forces it to be placed close to the object of scanning, so as not to lose resolution. At the same time (due to the wide angle) less than half of the spherical object is illuminated, in contrast to the almost parallel projection from a large distance.

mading
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Re: Laser Projectors and Scanning (LG HF80LA)

Post by mading » 31 Jan 2020, 11:59

Great news!
Was that model used by somebody in the old forum?
the 2000 lumens are very inviting for big stuff
HP 3D scan, Acer K132, LG PF50, 2x DMK23UX236, 2xComputar M1214, David Calibration panels, Melamine panels, DIY rotary table

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Micr0
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Re: Laser Projectors and Scanning (LG HF80LA)

Post by Micr0 » 31 Jan 2020, 16:33

OBNRacerMan wrote:
31 Jan 2020, 06:47
I can’t say anything significant about polarization (maybe it depends on the type of laser - because David Laserscanner saw laser pointers both red and green perfectly).
But I am much more confused by the moment of projection distance - those laser projectors that I saw are installed almost close to the screen (and, at the same time, they had a huge projection area.) - but this is definitely not suitable for scanning.
My projector also has a similar drawback - a too wide projection angle forces it to be placed close to the object of scanning, so as not to lose resolution. At the same time (due to the wide angle) less than half of the spherical object is illuminated, in contrast to the almost parallel projection from a large distance.
One of the features of laser based projectors is that they can have very short throw, however this one isn't. With exact measurements is seems very close to the PF1500 I'm currently using. We have an awesome electronics store here in NYC. Prices are usually the lowest in the country, and they have a no questions asked 30 day return policy. I can try the projector for a few days, and if it doesn't work I can return it for a full refund. If they had had one in stock yesterday I'd be scanning today. :)

As for David using lasers. I think there is a different algorithm that the software uses when capturing laser data vs SL data. It may take into account the problems with off axis reception of polarized light. I'm completely guessing here. It would be great to be able to talk to Sven again.....
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OBNRacerMan
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Re: Laser Projectors and Scanning (LG HF80LA)

Post by OBNRacerMan » 31 Jan 2020, 17:40

Micr0 wrote:
31 Jan 2020, 16:33
We have an awesome electronics store here in NYC. Prices are usually the lowest in the country, and they have a no questions asked 30 day return policy. I can try the projector for a few days, and if it doesn't work I can return it for a full refund. If they had had one in stock yesterday I'd be scanning today. :)
That is somewhere very far from my reality ... :D
In Russia, a projector of this model costs three of my monthly salaries ... so at this time I don’t even dream of a good FullHD projector ...
P.S. My very cool computer, along with a 27 "FullHD IPS monitor, costs less than such a good projector ... The only thing I can afford to change my UFO R9 projector in the future - is Xiaomi Mia Lite - such are the costs of living. :D

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