3D scanning - high resolution for small objects

Write here about construction, ideas, equipment, tips n tricks etc. related to structured light scanning
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OBNRacerMan
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Location: Obninsk, Russia

Re: 3D scanning - high resolution for small objects

Post by OBNRacerMan »

Micr0 wrote: 10 Jan 2021, 16:11 I guess we will all have to upgrade to 4K projectors. :)
I do not know yet "real" 4k projectors (mostly there is pixel shift technology). While this is about the same as in cheap models from the DMD 0.23/0.33" 1366 * 768 matrix they make FullHD, but here they get 4k from the FullHD DMD 0.47" matrix. And pixel shift systems don't perform well in scanning.

P.S. Still, it is more correct not to chase the megapixel, but using an honest FullHD projector to reduce (in any way possible) its illumination field - the result will be good, and the price is acceptable.
Soft: RangeVision DIY, Calibration panel/Rotary tables - RangeVision, Prj: Byintek UFO R9, Cam: Daheng Mercury MER-630-60U3M-L (USB3.0, monochrome) x2, Obj: ZLKC HM1628MP10 (F2.8, 10Mp, 16mm) x2 & Azure 3518M3M (F1.8, 3Mp, 35mm).
kth307000
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Joined: 17 Jul 2020, 15:35

Re: 3D scanning - high resolution for small objects

Post by kth307000 »

OBNRacerMan wrote: 10 Jan 2021, 16:39
Micr0 wrote: 10 Jan 2021, 16:11 I guess we will all have to upgrade to 4K projectors. :)
I do not know yet "real" 4k projectors (mostly there is pixel shift technology). While this is about the same as in cheap models from the DMD 0.23/0.33" 1366 * 768 matrix they make FullHD, but here they get 4k from the FullHD DMD 0.47" matrix. And pixel shift systems don't perform well in scanning.

P.S. Still, it is more correct not to chase the megapixel, but using an honest FullHD projector to reduce (in any way possible) its illumination field - the result will be good, and the price is acceptable.
Hello OBNRacerMan
Thank you for always good information.

I recently purchased the product below to replace the projector.
https://ko.aliexpress.com/item/32842506 ... 46db9bt_bt searchweb0_0,searchweb201602_,searchweb201603_

However, when tested, the screen is too large to be projected properly at the distance required for scanning.
I want to make the screen smaller, but it doesn't get smaller.
There are not many options that can be set, so I tried various things, but I think it is not suitable for scanning.

It would be helpful if you recommend a projector that is inexpensive.

Thank you.
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OBNRacerMan
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Re: 3D scanning - high resolution for small objects

Post by OBNRacerMan »

Among the newer projector models, there are almost no options with suitable specifications. All manufacturers try to make the picture bigger by reducing the projection ratio.
One of the best for use in a scanner is the LG PF1500, but the model is old and difficult to find even used on sale.
Soft: RangeVision DIY, Calibration panel/Rotary tables - RangeVision, Prj: Byintek UFO R9, Cam: Daheng Mercury MER-630-60U3M-L (USB3.0, monochrome) x2, Obj: ZLKC HM1628MP10 (F2.8, 10Mp, 16mm) x2 & Azure 3518M3M (F1.8, 3Mp, 35mm).
kth307000
Posts: 24
Joined: 17 Jul 2020, 15:35

Re: 3D scanning - high resolution for small objects

Post by kth307000 »

OBNRacerMan wrote: 16 Jan 2021, 08:17 Among the newer projector models, there are almost no options with suitable specifications. All manufacturers try to make the picture bigger by reducing the projection ratio.
One of the best for use in a scanner is the LG PF1500, but the model is old and difficult to find even used on sale.
Thank you for good information.
When you search for LG PF1500 in Korea, it is sold as the latest model.
Isn't the model number different?
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OBNRacerMan
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Re: 3D scanning - high resolution for small objects

Post by OBNRacerMan »

I know that in Russia it is almost impossible to buy PF1500 (or its next generation - HF60). If such an advertisement comes across, then the projector instantly "leaves". We have an average price for such a used one in good condition around USD550-750
P.S. I am not aware of the exact differences in the versions of this model for different regions.
Soft: RangeVision DIY, Calibration panel/Rotary tables - RangeVision, Prj: Byintek UFO R9, Cam: Daheng Mercury MER-630-60U3M-L (USB3.0, monochrome) x2, Obj: ZLKC HM1628MP10 (F2.8, 10Mp, 16mm) x2 & Azure 3518M3M (F1.8, 3Mp, 35mm).
barryvanbakel
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Joined: 02 Jan 2021, 14:58

Re: 3D scanning - high resolution for small objects

Post by barryvanbakel »

What is the throw ration of the LG?

"My HD projector (1280 * 720) has a throw ratio of 1: 1.47 with a focusing of 100mm, AAXA projectors have a TR 1: 1.2 "
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OBNRacerMan
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Re: 3D scanning - high resolution for small objects

Post by OBNRacerMan »

barryvanbakel wrote: 19 Jan 2021, 19:06 What is the throw ration of the LG?
LG PF1500 TR 1.40:1 - 1.54:1 (this model has a working optical zoom (not to be confused with digital zoom, which spoils the picture))
Soft: RangeVision DIY, Calibration panel/Rotary tables - RangeVision, Prj: Byintek UFO R9, Cam: Daheng Mercury MER-630-60U3M-L (USB3.0, monochrome) x2, Obj: ZLKC HM1628MP10 (F2.8, 10Mp, 16mm) x2 & Azure 3518M3M (F1.8, 3Mp, 35mm).
barryvanbakel
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Re: 3D scanning - high resolution for small objects

Post by barryvanbakel »

Forgive me to ask so many questions,

Does the optical zoom mean that you can use this projector (LG PF1500) for both very small objects, and also larger subjects such as a chair?
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OBNRacerMan
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Re: 3D scanning - high resolution for small objects

Post by OBNRacerMan »

barryvanbakel wrote: 27 Jan 2021, 09:10 Forgive me to ask so many questions,

Does the optical zoom mean that you can use this projector (LG PF1500) for both very small objects, and also larger subjects such as a chair?
I would say this - if there is an optical zoom, for all types of scanning, it is best to leave it in the position where the projector shows the smallest picture (at the same time, this projector will have a very good throw rate - ~ 1.5:1).
In the work of the scanner, the zoom is practically not needed, because the larger the object, the larger the calibration panel is used, and the farther from the object the scanner will be located, automatically increasing the size of the illuminated area (and cameras will also capture a larger area).
Soft: RangeVision DIY, Calibration panel/Rotary tables - RangeVision, Prj: Byintek UFO R9, Cam: Daheng Mercury MER-630-60U3M-L (USB3.0, monochrome) x2, Obj: ZLKC HM1628MP10 (F2.8, 10Mp, 16mm) x2 & Azure 3518M3M (F1.8, 3Mp, 35mm).
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Micr0
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Re: 3D scanning - high resolution for small objects

Post by Micr0 »

OBNRacerMan wrote: 27 Jan 2021, 09:25
barryvanbakel wrote: 27 Jan 2021, 09:10 Forgive me to ask so many questions,

Does the optical zoom mean that you can use this projector (LG PF1500) for both very small objects, and also larger subjects such as a chair?
I would say this - if there is an optical zoom, for all types of scanning, it is best to leave it in the position where the projector shows the smallest picture (at the same time, this projector will have a very good throw rate - ~ 1.5:1).
In the work of the scanner, the zoom is practically not needed, because the larger the object, the larger the calibration panel is used, and the farther from the object the scanner will be located, automatically increasing the size of the illuminated area (and cameras will also capture a larger area).
To add: What he said will somewhat depend on the focal length of you camera lenses. I have a PF1500 (it's a great projector for scanning) but the zoom lens is very limited and is really only meant for adjusting the image to fit a projector screen when you can't physically move the projector. However with the image set to it's smallest, the projector throw is much better for scanning than the much shorter throw projectors that seem to be all over the market now.
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